AGTireTalk The Future of Tire Technology 2020-04-03T02:54:41Z hourly 1 2000-01-01T12:00+00:00 Galileo Inverted Sidewall AG Tire 2020-04-01T19:54:48Z After the tradition defying appearance of Galileo AG Tire Product caught our eye, we caught up with Galileo staff to get the rundown of what this product is all about in the following interview with Mike Gelbman, VP of Sales USA:

1. What makes Galileo Cup Wheel unique?
Cup wheel is an innovation in manufacturing process…pneumatic tire with concave sidewalls, providing following attributes:
a. Elongated Rectangular Footprint with more even weight distribution to reduce soil compaction and improve traction- literally the characteristics of a rubber track without the ground compaction.
b. Even Side-Hill Footprint for improved stability.
c. Reduced Hazard Susceptibility due to cup shaped design.
d. Huge Improvement in Ride Comfort.

2. Is Galileo built with standard ag tire manufacturing equipment?
Yes, it is manufactured in the exact same radial ag tire production line in existing molds using our proprietary modifications.

3. Can Galileo be mounted to standard wheel?
Yes, and can be mounted to any wheels that came original equipment fitted with standard pneumatic tires.

4. Can standard ag tire mounting equipment be used?
a. Yes, standard large ag tire mounting machines can be used.
b. Pry Bars cannot be used- so service truck is not an option – although our skid steer is mountable this way.

5. What does a producer do if they encounter a hazard / air loss in the field?
a. Sidewall damage isn’t a factor due to CupWheel design and you get to finish your day / task; no bulging sidewall as with conventional pneumatic.
b. If air loss is encountered due to a tread puncture, CupWheel allows producer to finish the job and get off the field- with no air.

6. What design feature lends itself to improved lateral stability?
Unique inverted and reinforced sidewall design takes the lateral forces vs. the air in radial tires. So even at low air pressure Galileo has superior lateral stability.

7. What should producer expect cost difference to be vs pneumatic tires?
CupWheel is a premium product; will cost producer slightly more than a VF tire.

8. What is your sales platform for N America & Western Europe?
We are focusing on the Galileo CupWheel brand and support it with both OE testing and innovative and select aftermarket customers.

9. How does tire perform from a durability standpoint.
a. Sidewall damage is almost entirely mitigated as we basically don’t have one!
b. We’ve had no problem with V-shaped hinge point withstanding same amount of cycle times as standard pneumatic and the tire is entirely retreadable.

10. Does Central Tire Inflation System improve performance in line with pneumatic?
Yes, Central Tire Inflation System will achieve same objective with Galileo as standard pneumatic; however, our air chamber is smaller, enabling faster fill and deflation.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

AG TIRE SIZE OPTIONS / CONVERSIONS: Why, When, How ? 2020-03-02T16:05:07Z  


TRELLEBORG, “There is not a tire combination that is a “one size fits all” situation and often different operations would require different sets of tires for the same equipment.”

TITAN, “The tire industry has developed the RCI (Rolling Circumference Index) system based on the OD (Overall Diameter) of tires to assist manufacturers in the proper of selection of tire size combinations that will work.”

CONTINENTAL, “The Rolling Circumference Index (RCI) is a grouping of tires based on the rolling circumferences. The next higher RCI is always ~5.4% higher (+/- .2 % Tolerance), which means a factor of ~1.054.”

ALLIANCE, “If you are working with the Rolling Circumference Index group system, most MFWD tractors need to have fronts and rears that are 5 steps apart in the RCI, like a 50 Group in the rear and a 45 Group for the fronts.”

MAXAM, “If you have too much positive slip ratio (above 5%) you will have “excessive” work by the front tires pulling the rear tires equates to a loss of efficiency and higher fuel consumption. If you have a “negative” slip result, the front tires will experience a braking effect that creates a loss of pulling power, more fuel consumption and reduced steering capability.”

PRECISION INFLATION, “It is important to remember that RCI is a great guide; however, sometimes a tire will have a rolling circumference between groups or have variation between manufacturers- that is why we recommend contacting your local tire dealer to ensure lead lag is correct based on ACTUAL Rolling Circumference.”

BKT, “Because of the increased air pressures and load carrying capacities of IF/VF tires, it would be wise to check the standard wheels being used. Make sure they are built to handle the higher pressures and loads these tires will carry.”


Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

Modern Agriculture requires different kinds of tires (size, tread pattern, technology) for different applications and conditions in order to increase productivity, reduce compaction, increase flotation, reduce equipment damage and increase operator’s comfort. There is not a tire combination that is a “one size fits all” situation and often different operations would require different sets of tires for the same equipment. A typical case is with sprayers, where during crop applications “skinny” tires are used to reduce crop damage and large flotation tires are used for broadband application without a crop standing.

Equipment like sprayers (same size tires all around the equipment) or equipment with hydrostatic drive (like combines) are not affected by mandatory equivalent rolling circumference when changing tire sizes. However, with front wheel drive tractors (MFWD) the relationship between the front and the rear axle, called interaxle ratio, must be maintained in order to have the best traction performance and to avoid transmission issues. The front tires must always turn faster than the rear tires as they are smaller and need more revolutions to cover the same distance. In addition to this “faster” front tire rotation (depending on the interaxle ratio), the front tires rotational speed needs to be 1 to 4% higher than the rears to assure the grip and to help with steering. This additional rotational speed is called front axle lead. If the front tires cover less distance than the rear tires, they would create a braking effect with potential transmission damage. This is called front axle lag (we need to avoid this).

In order to make life easier for producers looking to change tires to a different size, the Tire and Rim Association (TRA) created an index called Rolling Circumference Index (RCI) to assist in tire size selections. This Index is created using the tire’s Rolling Circumference (RC). According to the RC, each tire is then placed in a RCI group. Each RCI group has a logical, even progression of RC where each RC is 5.4% larger than previous one. What is important when selecting different tire sizes is that the difference between the rear tire RCI and the front tire RCI is the same as the tires being replaced. This will maintain the correct RC ratios to insure proper front axle lead. For example, a front RCI 38 and rear RCI 43 (43-38=5) should have the same ratio as a front RCI 43 and rear RCI 48 (48-43=5). This is the value referred to by some OEMs when they mention that the ratio between the front and rear axles is 5 steps. For a tire size to be considered within a specific RCI, the calculated RCI of the tire must be between -0.2 to +0.2 of the RCI for that group.

Here are some points to consider:

1) Tire size – Each standardized tire size has theoretical calculated dimensions called nominal values. These dimensions allow for +/- tolerances and depending on the manufacturer’s tire brand, the same tire size may have a different RC. These differences could allow, depending on the tire brand and their tolerances, the same tire size from one brand to be included in one RCI group and another brand tire to be included in a different RCI group. This is the reason why specific tire combinations are offered by OEM in some tire brands and not in others.

2) Tread pattern – A R-1 tire’s RC is smaller than its R-1W counterpart of the same size and the same brand. It’s suggested not to mix tread patterns.

3) RCI spread – Not all tire sizes can be assigned to specific RCI group (remember the -0.2 to +0.2 spread of RCI) and some will fall outside this spread. For example, if the formula result for a specific tire size and brand is 47.5, it would not have an RCI (for RCI 47 you would include the range from 46.8 to 47.2 and for RCI 48 it includes from 47.8 to 48.2).

4) Load and inflation pressure – the RC specified for each tire size and model in the Tire Manufacturer Databook is measured when the tire is set at nominal inflation pressure and under nominal load. The tire RC will change (not too much) depending the inflation pressure used for the load on that specific equipment. OEM engineers physically test each tire combination using the correct inflation pressure for the load before they release these tire combinations and offer them for sale.

In order to be able to consider all tires (including the ones out of the RCI spread) and to assure we have correct front axle lead; we need to use the actual Rolling Circumference (RC) of both tires and the interaxle ratio for that specific tractor model for our calculations. This interaxle ratio will change depending the tractor model, type of transmission and the front axle configuration. Your equipment should be able to get this information and calculate if the desired tire combination will have an acceptable front lead.

RCI is a good initial guidance when changing tire sizes but always check to have the right interaxle lead percentage to avoid transmission damage.


Alliance Tire Americas
Nick Phillippi: National Product Manager

When it comes to a tire/wheel conversion, step one is to determine the goal or the need of the equipment. What isn’t it doing or what do you want it to do better? Then determine if you’re doing all you can with what you have. For instance, are you operating at the optimal inflation pressure? Is your machine ballasted properly? Lastly, seek out all the options to really determine which makes most sense. Although there can be benefits to switching to taller or wider tires, they are not always the best choice.

Determine if you already have the correct size, load index and type of tread on the unit before you move to make major changes.

If you’re looking for more footprint and thinking about a larger tire, you need to be sure you won’t have too much tire— if your tires are too big, you won’t be able to gain what you want as insufficient weight will not provide full footprint at low inflation pressures. Also be sure you understand the air pressure requirements at different operating loads and speeds and determine if you are going to be able or willing to make changes on air in the field. You may have a situation where you have the right tires, but need a central tire inflation system (CTIS) to take advantage of them.

Most tire/wheel conversions are done to gain footprint or increase tire volume (actually, they’re both the same thing), lowering air pressure and thereby reducing compaction. But, before you jump to expensive or complicated solutions, first determine if moving from a bias to radial, or from a standard radial to VF, or finding a tire with a larger overall diameter that can be mounted on the same rim can get you to the target goal.

One of my favorite up-fitment examples for a very popular tractor setup is switching out 480/80R50 and 380/80R38 sets to VF480/95R50 and VF380/95R38 sets. You don’t need a rim change, there are normally no clearance issues, and you can lower ground pressure by up to 52%.

Important: whenever you change sizes on MFWD units, you must maintain the correct lead/lag by keeping in mind the RCI—the Rolling Circumference Index, which factors in the length on the ground of one full rotation and the height of the tire (don’t worry, it’s on a chart from your tire manufacturer). The index is a grouping of tires that are all within about 4 inches of each other in outer diameter (OD).

Basically, your tractor is designed around a very specific ratio between the RCIs of your front and rear tires, so to avoid excess tire wear or even destroying your transmission or transfer case, you must change the front and rears in the same percentage.

In the above example, we took off rears that had a rolling circumference of 240.7 inches and replaced them with tires with rolling circumferences of 256.6 inches, a difference of 6%. Same way with the fronts: we moved from rolling circumference of 183.3 inches to 195.2 inches—or the same 6%, to maintain the same front-to rear-ratio. Be careful—even standard R-1 tires of a particular size from two different manufacturers—or different designs from the same manufacturer—may vary slightly on RCI, so double check them all. You need to keep the change the same or at least within 2%.

If you are working with the Rolling Circumference Index group system, most MFWD tractors need to have fronts and rears that are 5 steps apart in the RCI, like a 50 Group in the rear and a 45 Group for the fronts. At Alliance Tire, we prefer to provide the actual number of inches in the rolling circumference so you can be extremely accurate about your choices.

Regardless of which RCI system you use, when you’ve picked out the options, it’s always good to get that second opinion from your equipment dealer or experienced farm tire technician. Be careful: “close” may not be close enough, and it will be an expensive lesson.

Some conversions are done to increase traction, reducing slip and thereby saving on fuel. Again, before you invest in new tires and rims, be sure you are already at the correct and lowest air pressure and see if moving to VF tires or perhaps just a slightly wider or taller tire on the same rim can meet your needs.

As with any investment, it’s not just enough to say you will save money (or fuel or time) or reduce compaction. You need to compare the likely savings to the cost and really see if the payback will be worth the payment.

Also, are you making the decision based on an unusual season, a unique event ,or small part of your overall operation? If so, be sure the investment will pay out over the normal operations and normal conditions that you will be farming in. Is there another way that might be less costly for those small windows of need, like leasing another unit for short periods?

Selecting the right tire/rim combination and using it to its best advantage can be a very powerful way to get the most performance and efficiency from your equipment. It can be worth every penny you invest, and then some. But before you make the leap, make sure you really need it, and talk to your tire dealer for advice so you know you’re making a great investment and using it well.


Precision Inflation, LLC
Ken Brodbeck, VP of Technology

When & How to Use RCI Chart

The large majority of tractors in the 100 to 400 hp range are set up to go between 30 inch-wide rows.

But what about 20” rows or bedded vegetable crops?  Narrower tires are in order.

And what if the 360 hp Mechanical Front Wheel Drive (MFWD) machine is the big horse on the farm?  We may need wider tires, not those wimpy 480 mm wide things!

So how do we find the new set of tires and keep the proper front/rear tire gear ratio required by the tractor manufacturer?

Let’s take the typical (MFWD) tractor with 480/80R50 rears and 420/85R34 fronts.  This is defined as a “5 Step Tractor.” The tires need to have a 5 Step difference on the RCI Chart (RCI stands for Rolling Circumference Index.)  RCI 48 – 43 = 5 Step difference between front and rear tires.  Going to a smaller diameter front and rear will work as well by selecting any tire from RCI 47 rear – 42 = 5 Steps.

Alternate Section Widths (mm) Range

The chart below has popular 5 Step MFWD tractor RCI 48 480/80R50 rears and RCI 43 420/85R34 fronts, showing alternate wider and narrower rear and front sizes highlighted below.

Narrower Section Widths (mm) Range

If you are looking for narrower options, simply move to the left of the RCI 48 480/80R50 for rear tire options, then move to the left of RCI 43 420/85R34 for front tire options.

Wider Section Widths (mm) Range

If you are looking for wider options, simply move to the right of the RCI 48 480/80R50 for rear tire options, then move to the right of RCI 43 420/85R34 for front tire options.

Alternate Set Ups & Important Checks

Remember, tires are considered part of the tractor transmission.  While most MFWD tractors have “5 Steps” between the front and rear tires, there are some 4 and 6 Step tractors out there.  Always contact the tractor manufacturer to be sure.  For some select large Deere tractors, you can look at the frame for indicator:

In the case of a 4-Step Tractor, you simply select a RCI 48 Rear and matching RCI 44 Front.

RCI 48 – 42 = 4 Step difference between front and rear tires.

It is important to remember that RCI is a great guide; however, sometimes a tire will have a rolling circumference between groups or have variation between manufacturers- that is why we recommend contacting your local tire dealer to ensure lead lag is correct based on ACTUAL Rolling Circumference.

Lastly, it is important to contact your local tire dealer before making final selection of tires to make sure equipment has sufficient clearances for desired options and that front and rear widths correlate for application.

For getting the first pass options narrowed down, nothing beats the RCI Chart!


Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

There are many occasions when an end user is looking to change the tire set up on their tractors, such as going from narrower row crop section widths to more of a floatation configuration.  On the other hand, in the case of utility and compact tractors moving away from an Ag bar design to and industrial lug design, both of these are fairly common.  The thing that the end user needs to consider is the gear ratio of the tractor and the lead/lag ratio.  Front tires typically are spinning 1%-5% faster than the rears.  This ratio is important in the performance of the tractor.

Most North American MFWD tractors have a gear ratio of approximately 1.332.  The tire industry has developed the RCI (Rolling Circumference Index) system based on the OD of tires to assist manufacturers in the proper of selection of tire size combinations that will work.  There are charts available that show the different sizes and their perspective RCI values.  An example is the 480/80R50 rear and 380/80R38 combination on MFWD.  The rear tire is considered a group 48 RCI and the front is considered a group 43 RCI.  The difference in those two groups is 5.  That is called a 5 step drop.  The idea is as long as the rear and front RCI’s are 5 steps apart they will work on the tractor.   You can match a group 49 with a group 44 or group 47 with a group 42 and they will work fine on the tractor.  Fig. 1 is an RCI chart showing the different sizes and their perspective RCI’s.  This is a great tool to use when selecting different options for your tractors.

Titan offers an online lead/lag calculator to assist in the selection of tires.  By entering the published rolling circumference of the front, rear or both and the gear ratio of the tractor it will tell you the target rolling circumferences of the tires that are needed to make the combination work.

If the lead/lag is not correct there can be issues with the tractors performance.  For instance if the front tires are not changed the rear tires OD increases, this will put the tractor into a negative lead/lag meaning the rear tires will be pushing the fronts which could lead to the differential binding up and potentially locking up.  If the front tires OD are increased without and change to the rear the tractor will have a higher over travel, which means the tires will be spinning too fast causing faster wear and potential issues with the tractor not disengaging from the front wheel assist without some work.

Whenever changing the fitment it is best to do the research and understanding what is currently on the tractor and what the RCI drop is from rear to front.  Once that is understood it is relatively easy to identify sizes in the appropriate RCI that will work.  Local tire dealers are also a great resource in navigating through the appropriate options for the best fitment.  On a final note, when moving to a larger OD tire on a  tractor although the lead/lag is correct, it is important to verify that the tires will clear all the fenders, frames, fuel tanks and toolboxes to ensure the new tire will fit into that particular envelope on the machine.


Michelin Ag
David Graden: Operational Market Manager – Agriculture

Most commonly, a producer or tire dealer will use lead/lag calculations or RCI (rolling circumference index) when converting tires and wheels from duals to wide singles, converting bias to radial, old standard radial tires to newer metric tires, etc. The purpose of this would be to increase flotation, reduce soil compaction, lower fuel consumption or improve productivity.

Rolling Circumference Index (RCI) is commonly used to match front and rear tires to each other within a given gear ratio. For example, a certain John Deere machine may have a “5 step” transmission. Well, a 480/80R50 Michelin Agribib 2 has an RCI of 43, therefore it will match several front sizes that have an RCI of 43 (13.6R38, 420/85R34, 380/80R38, etc.) If you look in the Michelin data book, however, not all tires have a published RCI. This is where you have to be careful. Michelin does not publish RCI for all tires because some tires may fall within a grey area, meaning depending on the load and inflation pressure, these tires will fall within one of two RCI numbers.

In the instance where RCI is not available, you may need to calculate the mechanical lead. Most tractor manufacturers impose a mechanical lead of between 0% and 6%. This lead is specific and may vary depending on the manufacturer and the vehicle. See the following calculation:


  • You have an older Ford-New Holland 8970 equipped with 16.9R30 front tires and 480/80R46 rear tires
  • All tires are worn out & customer wants to replace them with Michelin Agribib 2
  • You look in the owner’s manual and find the tractor has a Mechanical Ratio = 1.35
  • Will the Michelin 420/90R30 and 480/80R46 Agribib 2 give an acceptable lead?


  • 420/90R30 Agribib 2 has an RC = 177.7 in
  • 480/80R46 Agribib 2 has an RC = 228.5 in
  • Mechanical Ratio/inter-axle ratio = 1.35

  • In this instance, yes; the proposed Michelin Agribib 2 tires will fit within the manufacturer’s specifications

It is very important you keep this in mind when are converting one size of tire to another, or in some cases, even between tire manufacturers. If your tires are mismatched with respect to the mechanical lead ratio of your machine, you would experience increased fuel consumption, erratic or rapid front/rear tire wear, wear and tear on your transmission, and overall poor tractor performance.

If you need assistance with this, all Michelin Ag reps are equipped with the tools and knowledge to walk you through this.


Continental Agriculture North America
Harm-Hendrik Lange: Customer Solutions Engineer for Continental Commercial Specialty Tires (CST)

The first thing to consider is the vehicle’s/tractor’s operators manual and what is written about tires and tire exchange. Many tractors have special requirements. While general recommendations vary in the percentage values of proper lead (often 0% – 5%), many manufactures have a smaller tolerance band for specific tractor types, so this needs to be considered when changing tires.

We recommend the check to confirm the lead and acceptable technical data for each tire change individually. Requirements for different tractors are individual due to the variation of technical data of a specific tire size produced by different manufacturers. Even the data from the same tire manufacturer may vary for the same tire size, if multiple tire lines exist or if there are tires with different load indexes within the same tire line.

For traction and soil compaction (and maybe also for optics), it’s recommended to always choose the highest RCI option the OE permits for the vehicle type, if there are not specific reasons to divert from this theory. Factors that could lead to smaller tire diameters:

– If the total height of the vehicle needs to be limited. For example, operating in low buildings or if a lower center of gravity is required (for use on steep inclines).

– If the turning diameter needs to be optimized. Smaller tires on a steering axle would allow for sharper steering angles.

Of course, more tire width and more section height normally mean more air volume = load capacity at the same inflation pressure. If there is no limitation from that perspective (like row applications or plowing in a furrow), maximum permitted values are recommended for maximum performance on the field.

If the tractor is mainly used for field work, lead percentage may be chosen on the upper tolerance of the permitted tolerance band, as little higher lead values allow sharper field end turning with engaged MFWD compared to lower lead values. If the lead is very low, a tractor tends to go straight even with turned steering wheels, like it does when diff lock is engaged.

On the other hand, if a tractor operates part time or is on road often, lower lead values may be considered. Even if the MFWD is switched off on road normally, many tractors engage MFWD while braking, so high lead values may create high tension in the drive line.

Example: OE allows 1.0 – 3.5% lead. One tire combination would end up in 1.1% lead and the alternative one on 3.4%. For a field work tractor, I would use the 3.4% option, for a tractor used often in road transport, I would choose the 1.1% lead option.

What´s behind the RCI values?  The Rolling Circumference Index (RCI) is a grouping of tires based on the rolling circumferences. The next higher RCI is always ~5.4% higher (+/- .2 % Tolerance), which means a factor of ~1.054. The RCIs in the tractor´s handbook can give 2 different kinds of information:

  • The maximum RCI that is permitted (including the front tires for pairing).
  • What the RCI difference is between the front and rear axle, as this should be kept constant.

Example: The RCI ratio between 41 on the front and 46 on the rear is 5 (46 – 41= 5). If your tractor manufacturer alternatively allows you to increase to RCI 47 tires on the rear axle, the front axle should then also increase to 42 to keep the difference of 5 RCIs constant.

What does this example mean to the lead value?

The tire circumference difference can theoretically be calculated by the RCIs or the RCI difference:

  • RCI difference = 5 = 1.054 x 1.054 x1.054 x 1.054 x1.054 = 1.054 ^5 = 1.30
  • Old tires RCI 41 & RCI 46: (4275mm & 5550mm) = 5550 / 4275 = 1.30
  • New tires RCI 42 & RCI 47: (4505mm & 5850mm) = 5850 / 4505 = 1.30

For example, if the transmission ratio is 1.27 and the tire circumference ratio is 1.30, this would mean 2.36% lead for all tire combinations with 5 RCIs difference (1.30/1.27 = 1.0236) on this machine.

Nevertheless, as the real exact rolling circumference values can vary from the theoretical RCI numbers, the most precise calculation is reached by using the real rolling circumference data from the tire’s datasheet instead of the RCIs.


CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

There are several situations when a farmer should consider converting his current wheel/tire setup to an alternative configuration. The main issue to consider is what are your goals? Typically, a farmer wants to produce the highest yield with the best quality at the least cost of production. This will maximize the return which is why farmers are in the business of making money!

Compaction: If a farmer determines that compaction is limiting his ability to produce the highest yields and quality, an assessment needs to occur to identify the cause of the compaction. An action plan to correct the compaction problem needs to be developed and implemented. Converting tire sizes to reduce compaction can help by reducing ground pressure from your equipment. If you run bias tires during field operations you can simply change to radial tires or to the “IF” or “VF” to reduce ground pressure as well as increase traction. If converting to these higher technology type of tires does not satisfy ground pressure reduction goals then you may opt for a wheel/tire conversion to tires with a larger air chamber. You can decrease ground pressure by increasing the air chamber which can allow for higher load carrying capacities. These conversions can be via larger diameter, wider section width tires or both but will typically need rim changes also. There are options available to decrease your ground pressures and the best option for your operation should be investigated. Keep in mind that when changing tire sizes on front wheel assist tractors you need to maintain your lead/lag ratios to enable the tractor to operate mechanically within the design parameters.

Traction: If you have trouble pulling implements in high torque applications, grain carts or any other application with a reasonable amount of slip you may need to increase your traction. You might need to replace worn tires that don’t have enough lug depth left to give you the traction required or you may need to change your tire set-up. If you run bias tires by chance you can make drastic improvements by switching to the same size in a radial tire. If you are running radials you may want to consider changing to an “IF” or “VF” type of tire of the same size. The “IF” and “VF” tires not only carry more weight than a conventional radial tire at the same air pressures, they have a larger footprint. The footprints are enlarged due to the sidewall deflection which will grow the footprints in length. Growing the footprint in length will increase traction. Tire/wheel conversions for traction reasons is not very common since these conversions would likely be to a narrower tire that will increase traction but also increases ground pressure along with compaction potential.

Flotation: Flotation problems are encountered at times and harvest time is certainly a critical time. If you can’t harvest your crops due to wet soils you probably need to convert your combines to a flotation setup. Combine conversions to a flotation setup is usually a drastic change to maximum flotation. How much flotation do you need? Who really knows until after the fact so consider the most flotation you can justify.

Summary: When wheel/tire conversions are needed or wanted, you need to consider the best options that will help accomplish your goals. Conversions are expensive and they need to be done correctly to get the most benefit you can get.


Dave Paulk: Manager Field Technical Services

There are several instances where it might make sense to change or convert tire sizes and wheels on tractors.

Switching from bias tires to radial tires would be a smart move in the right circumstances. Radial tires generally provide better traction, less soil compaction, better comfort, and can be run at lower air pressures. Although many radial sizes match the bias sizes in a conversion, there are instances where they don’t.  In this situation, a person may have to change wheels and tires when converting to radial tires.

If narrower or wider tires are wanted or needed on MFWD’s (Mechanical Front Wheel Drive), in order to stay within the correct lead/lag ratio it will probably require changing out tires and wheels. These size changes are often required when going from wider to narrower rows, or vice versa.  MFWD tractors are 4-wheel drive vehicles with different sizes of tires on the front and the rear. The transmission must be geared so that both fronts and rears turn at basically the same speed, since the fronts will turn more revolutions. When changing sizes on MFWD’s, the +1-5% tolerance to the lead/lag ratio must be honored to alleviate any transmission/transaxle problems. By knowing what the front to rear gear ratio is on a tractor, a person can use the RCI (Rolling Circumference Index) data to stay within the required range for the tractor. The rolling circumference is the distance in inches that a tire travels in one revolution. When selecting a new tire size, a person must choose the same front and rear combination RCI that matches up with the original tires.  On MFWD tractors, if the fronts are too big and/or the rears are too small, the fronts will pull the rears (lead). If the fronts are too small, the rears will push the fronts (lag). They should both be turning at close to the same speed. It is necessary to be very careful when changing sizes on these tractors.

Changing tire sizes on 2-wheel drive tractors is straightforward. If both tires on an axle is changed, there should be no problems. The rims may have to changed depending on the size and the width of the tires used.

Tire sizes can be changed on full time 4-wheel drive tractors. These tractors have the same sizes of tires all the way around like a 4-wheel drive truck. If the same sizes are used on front and rear, there are no issues. Wheels will have to be changed because of the sizes and widths of the tires used.

When moving from a standard size tire to an IF/VF tire, manufacturers recommend a wider wheel to maximize the benefit these tires offer for weight carrying capacity and lower air pressures. BKT’s line of VF tires (V-Flecto) are designed as a Narrow Rim Option (NRO) and will work on the narrower standard rims. Because of the increased air pressures and load carrying capacities of IF/VF tires, it would be wise to check the standard wheels being used. Make sure they are built to handle the higher pressures and loads these tires will carry.


Maxam Tire International
Greg W. Gilland:  Business Development & Ag Segment Manager

Ag tires are designed by size or footprint to fulfill following specific functions:

  • Carry the Load
  • Transmit the Torque (or driving power)
  • Provide Direction
  • Allow the Chosen Equipment to fulfill its purpose

As the Ag industry has evolved from animal driven to 2WD tractors to mechanical front wheel assist tractors (MFWD / MFWA), tires have also evolved in design, materials, functionality and performance. Ag practices around the world differ based on crops grown, soil conditions, moisture content and environmental conditions. In order to provide solutions that are flexible to an evolving global market, the equipment manufacturers or OEMs offer their machinery with tires of different diameters or widths for the same machine to adapt their equipment to the specific needs of that grower or crop. One of the key tools that is used to adapt or convert tires from crop to crop or grower to grower is the RCI or rolling circumference index. The RCI is the rolling circumference or the distance a tire travels in one revolution. The advent of powered front axle tractors or mechanical front wheel assist / drive (MFWD) tractors to provide more power (torque) to pull implements in the field requires a clear understanding of the RCI impact. The smaller front tires must travel faster to stay in the same ratio or time that the larger rear tires travel as they roll. In other words, the front tires will turn more times as the tractors moves forward for every rear tire full revolution.

Each MFWD tractor must maintain a balance between “positive slippage” or front tires pulling, and “negative slippage” when the front tires are slower or lagging therefore resisting the push from the rear tires. This balance is the tractor gear ratio also known as, “the lead or lag ratio”.  As a rule, the “ideal” tractor gear ratio between the front axle and the rear axle (IAR or Inter-Axle Ration) ranges from 1.2 to 1.5. For the front tires to pull successfully and produce the right amount of pulling power with the right “slip” to stay within the tractor gear ratio, the proper tire slip needs to be between 1% to 5% = “positive slip”.

If you have too much positive slip ratio (above 5%) you will have “excessive” work by the front tires pulling the rear tires equates to a loss of efficiency and higher fuel consumption. If you have a “negative” slip result, the front tires will experience a braking effect that creates a loss of pulling power, more fuel consumption and reduced steering capability. Each OEM publishes their recommended Gear Ratio for each model MFWD or MFWA tractor they manufacture. Tire manufacturers should provide their tires’ rolling circumference (RC) or the RC Index (RCI) values in their published product data to allow growers to calculate the right size tire fitment from front to rear for their equipment to ensure the right amount of positive slippage or pulling power for the given gear ratio.

The Front to Rear Gear Ratio Tire Slippage Calculation is as follows:

(Front Tire RC x Tractor OEM Model Gear Ratio) / Rear Tire RC) – 1) 100 = Slip %

MAXAM publishes in our Ag catalog both the tires rolling circumference and the tire RCI value to assist growers in ensuring the tires chosen for their equipment can operate within their MFWD gear ratio limits or needs.  Growers, at times, will also consider changing tires by either selecting a bigger tire combination or width to improve their traction, flotation or pulling capability. Below is the MAXAM example of tires having similar diameters but different widths within the same RC or RCI to determine what is the best tire size suited to meet their field or crop production needs. Using the above equation and the RCI data, as well as the OEM tractor gear ratio, any grower can quickly determine if their equipment will allow switching or evolving to larger tires without compromising their required gear ratio slip rate percentage.

The MAXAM Ag tire catalog provides our tires’ RC, RCI and diameter specifications, to assist growers in determining any technical information necessary to support their equipment needs or potential tire size evolution.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

Traction & Flotation OPTIMIZATION 2019-12-31T02:36:59Z  


Precision Inflation, LLC
Ken Brodbeck, VP of Technology

Can you have great traction and flotation? YES! Let us start with a couple definitions:

Traction: The ability to generate forces in the field and transport.
– to move the machine forward (Pulling) and backward (Braking)
– to move the machine left or right (Steering.)
Flotation: The ability to keep the tire as close to the soil surface without sinking causing ruts, compaction and worst case, becoming stuck.
Tire Flat Plate Area: The area generated by the tire footprint (Measured around the outside edges of the tire lugs) at maximum load and pressure on a flat steel plate.

How to use Flat Plate Area to compare tires:

  • Do use flat plate area to compare tires within the same brand when comparing different sizes or Standard versus IF or VF in the same size.
  • Shy AWAY using flat plate to compare tire Brand X to Brand Y. Due to companies using different measurement techniques, the numbers are all slightly different.

Some will be bigger and some smaller, but they will carry the same load at the same psi.  The psi required is the MOST important factor!

Maximizing Traction:

  1. Increase weight
  2. Taller and/or wider tires
  3. Adding duals or triples
  4. Choosing premium IF or VF tires
  5. Most importantly, set pressure to the minimum per the load/inflation table

Maximizing Flotation and minimizing compaction:

  1. Removing excessive ballast, ie. Cast or liquid weight and extra tanks on a tractor
  2. Taller and/or wider tires
  3. Adding duals or triples
  4. Choosing premium IF or VF tires
  5. Choosing a Tire Inflation system to set tires to the optimum low pressure for field and the optimum higher pressure for transport

Does tire pressure really make that much difference?  The footprints below are on a sprayer and we only changed the pressure to show a VF vs. Standard tire footprint.

VF will provide great flotation at lower psi…………Std. tire will not float nearly as well at 50.

VF footprint will not wear as well on road………….Std. tire will wear best due to less squirm.

Bottom Line: You can have your cake and eat it too.

Just be sure to choose tires that can carry the tractor ballast between 8 to 14 psi with wheel slip in the 6 – 12% range.  You will then have the most fuel efficient and lowest compaction tractor, even compared to a track machine.


Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

Traction by definition is the force that causes a moving thing to stick against the surface it is moving along.  In the case of tractors, the ability to transmit the power of the tractor through the drive train and tires to the ground to do work such as pulling another piece of equipment.

Lack of traction can cause excessive tire to ground slip which equates to poor fuel efficiency and loss of productivity. This can be corrected in a number of different ways.  The first being that the tractors total weight is properly ballasted to the amount of horsepower.  Typically 100lbs to 120lbs per rated horsepower is the appropriate target.  The correct weight will utilize the tractive efficiency of the tires in order to transmit the power properly to the ground. In addition, proper tire inflation based on the load will maximize the tires footprint on the ground to maximize the traction. To improve traction the amount of ground bearing pressure under the tire’s footprint needs to be maximized.  It’s really pretty simple, a 250lb man with size 8 shoes has more traction than a 150lb man with size 8 shoes. The same can be said for tractors.

Floatation on the other hand by definition is the act, process, or state of floating or of causing or allowing something to float. In order to gain more floatation minimize the ground bearing pressures to increase the buoyancy or floatation of the machine. The heavier the machine the more ground contact area is needed to carry that load. Many growers remove ballast or for certain applications to minimize ground bearing pressures to minimize compaction issues usually during spring planting.

The trick comes with balancing the two, by definition and functionality in tractor applications they are the opposites. As you attempt to improve one you will inevitably be hurting the other. One methodology is to dual or even triple tires on equipment to increase the sq/in on the ground.  However, as with any dual or triple configuration depending on the soil conditions it will result in rutting or loose soil being pinched and a berm will be created between the tires.  The severity of that depends on how wet the soil actually is. Another downside is the overall width of the machine increases and creates a litany of new issues.

Another method which has been gaining popularity is to replace duals with super singles.  One large tire in place of two.  This immediately reduces the rutting in the field, and narrows up the machine making it easier to maneuver in tight areas.  Larger super singles like and LSW1100/45R46 rear replacing dual 480/80R50’s and the LSW1000/40R32 replacing 380/85R38 nets in a 20% increase in flotation for a MFWD.

This configuration is a great balance for this type of machine.  Traction improvements have been enjoyed while increasing the flotation of the machine

We have seen this same trend on 4WD machines.  Large super singles like the LSW1400/30R46 have been replacing standard 800/70R38 duals. Even though the overall square inches on the ground are slightly reduced, the floatation characteristics are improved.  Machines with the dual no matter the size will rut worse in fields which are saturated. In addition the overall width of the machine goes from 197” with the dual 800’s to 150” with the LSW1400’s.  Again, this combination has proven time and time again on a properly ballasted machines that this is that perfect balance of traction and floatation.

Understanding the give and takes between traction and floatation and understanding the dynamics of each gives growers a chance to choose the best fitment for their machines.


Alliance Tire Americas
Nick Phillippi: National Product Manager

Traction and flotation can have a complicated relationship: sometimes they work together and other times they can work against each other. Understanding both can help farmers make appropriate tire choices.

From a tire engineering standpoint, traction, or tractive force, is the maximum amount of force that a tire can place against the surface for forward movement.  It’s the measure of how much power the tire can deliver to the ground to move the vehicle forward without slipping. Once you’re slipping, your force is just moving the tire, not the machine.

Tire companies spend millions to design tires that can exert more force without slipping, using factors like tread and lug design, surface type, compounding and added featured like sipes or studs to increase the friction between a tire and the ground to increase its traction.

Flotation is the ability of an object, whether it’s a tire or a snowshoe, to remain on top of the surface. Another term for it is buoyancy. Overall footprint—the total number of square inches of tire in contact with the ground—is a good predictor of buoyancy. From the tire perspective, one might say that optimum flotation is the largest area of coverage to provide maximum traction while also exerting the least possible soil compaction pressure.

 Optimum flotation is going to be very dependent on soil types and soil conditions.

If you’re in sloppy, thin mud, wide tires can provide plenty of flotation to keep you on the surface, but that slick soil will offer very little traction. You’d probably end up throwing a rooster tail of mud behind you while getting nowhere and wasting a lot of fuel. That’s exactly the situation we designed our R-2 tire to tackle—instead of providing flotation and keeping the tractor on the surface, it digs down to firmer soil and gets traction with extra-deep lugs. That’s what you need to get the job done in the kind of slick mud where rice and sugar cane are grown.

On the other hand, if you’re in heavy soils where a shallower lug can gain traction but you want to minimize soil compaction and rutting, you want more moderately sized lugs and a really large footprint from wide flotation tires or long VF tires.

Of course, in farming, you don’t get the same conditions every day. The problem is that many people select tires based on the most extreme conditions they may encounter rather than on more typical use scenarios. That can lead to inappropriate choices. For instance, an R-2 tire may be really helpful for a week or so in a particularly wet Midwestern spring, but it would wear too quickly, ride rough and tear up your fields most of the year.

In recent years, we’ve been developing unique, new treads that allow farmers to really fine-tune their tire choices. In the hills of eastern Washington, our block tread Alliance 550 MultiUse radials have become extremely popular on self-leveling combines that run on steep, silty slopes because they aren’t prone to side-slipping. In forage crops, manure haulers look for the curved shoulders and massive block treads of our 393 and 398 high-speed flotation tires to prevent rutting and minimize compaction. And we’re just about to redefine what an R-1 lug looks like.

The bottom line is that you have to think about the conditions  you operate in over the course of a whole year. Do you want a rounded contact patch for digging into the soil—which is characteristic of a bias-ply tire—or the flatter, broader contact patch that you see with steel-belted radials? Think about what gets you through your soils, how much slip you can tolerate, how much compaction your soils can take, and what your tolerance is to the cost of fuel, tires and maintenance.

Just remember that flat plate—the square inches of your footprint and the number of lugs on the ground—is an important piece of data, but it’s not the only factor in choosing a tire.

Here are some tips to optimize your tire choice on a drive axle:

  1. Match your tire size and load index rating to the tractor weight and horsepower in the most common use.
  2. Choose the tread design that matches your soil and, in some cases, your application-specific need.
  3. Inflate your tires to the optimal air pressure for the most challenging loads and speeds at which you’ll be operating. It’s not convenient, but changing from higher pressure on the road to lower pressure in the field will provide the best performance in both conditions, maximizing safety and comfort and minimizing fuel consumption, wear and soil compaction. (This is why central tire inflation systems (CTIS) can improve tire performance so dramatically and pay off so quickly.)
  4. Don’t assume that buying the lowest cost tire is the best financial decision for your business. In many cases, premium tires provide benefits that will save you time, reduce fuel costs, decrease down time, increase productivity and cause less soil compaction. Those tires can often pay for themselves in a single season, depending on the size of your farm.

For free-rolling applications where forward traction is less relevant, the math changes a bit, but in most cases lateral traction and flotation (buoyancy) have high value to reduce drag—which costs wasted fuel—and minimize soil compaction.

Tire Pressure Matters

In the photos below, you can see the same tire inflated for roading (the 27 psi examples, with both “Planter Up” and “Planter Down”) and fieldwork (“Planter Down, 10 psi”). Look at the difference in footprint when the tire is set to pull the planter at road pressure—the center photo—vs. when its inflation pressure is set for fieldwork in the right-hand picture. You’ll see how many more lugs are in contact with the soil at 10 psi, and how much larger the footprint is. If you’re in pretty firm soil and you’re looking for traction and more flotation, this picture should speak a thousand words. (It should also make you consider investing in CTIS along with a great set of tires.)

As you can see, the proper pressure can have a dramatic impact on the footprint length, and, in the case of bias tires, even its width. Radial tires—especially steel belted ones—maintain a more constant footprint width.

Tire companies may disagree on a lot of things, but there is one topic on which even the bitterest of rivals will agree: inflating your tires to the proper pressure for the load and speed they’re operating under is by far the most important thing that you can do to maximize your traction, optimize your flotation, and to get the best performance out of your tire.


Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

In farming applications, traction and flotation tires have different operational tasks, although they are partly used together in many cases. The best example is a large slurry tanker being pulled by a large tractor on a field. We can compare both tire types in this exemplary application. What both tire types have in common is that they should carry the highest possible load with the lowest possible inflation pressure.

We already know:

Low Inflation Pressure => Larger Footprint => Less Soil Compression and Lower Track Depth

This means the lower the track depth, the less soil volume needs to be removed and deformed. So low inflation pressure means lower fuel consumption for both tire types, as well as less soil destruction and compression. It’s more efficient to deform the tire shape, than to deform the soil.

What´s the main difference between the traction and flotation tire applications?

For creating traction, and to have the maximum footprint possible, it’s often required to have the maximum number of lugs connected with the ground. But sometimes, maximum traction requires getting through a small layer of wet mud or loose surface material to get the grip of the more solid soil layers below. This means a little increased tire pressure can, in certain cases, even increase the traction potential, but this always depends on the actual situation of the ground.

In contrast to the traction tire, the flotation tire in implement application does not need to create so much grip, except by some brake force or side force transfer in hilly field operations. The main task of the flotation tire is:

  • Reduced rolling resistance for low pulling force at high loads, especially on deformable surfaces, like dry sand or wet (clay) soils
  • As the soil destruction potential of the complete vehicle combination (tractor plus trailer/implement) is generated by the tire with the highest inflation pressure, the air pressure in the flotation tires (implement or trailer tires) should not be much higher than the inflation pressure of the tractor tires
  • While a driven tire actively works against the “bulldozing effect” by rotating, a non-driven tire needs to be turned by outer forces. With deeper track depth and small tires, the “bulldozing effect” becomes more and more significant as the tire is pulled against the soil wave (picture below). This means small tires with higher inflation pressure waste much more energy to fight against the soil wave in front of the tire.

As the space on the vehicle/trailer is defined, the maximum diameter of the tires is limited. This requires the flotation tires to compensate the required air volume for load capacity by maximum width and maximum sidewall height.

Tests performed by Prof. Dr. Ludwig Volk of the University of Soest showed on a 4-axle slurry tanker that the pull power demand can be reduced from 208 hp down to 147 hp by reducing the inflation pressure of the flotation tires from 58 psi to 14.5 psi on the field. The main driver for this efficiency effect is the difference in track depth, which was reduced from 5.9 inches at 58 psi down to 3.15 inches at 14.5 psi.

Flotation tires should show comparable sidewall flexibility like a tractor traction tire to give them the ability to operate with low inflation pressures. In contrast to that, truck tires which are still often used for agricultural trailers, don´t have this special side wall design for flexibility.


CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

Ag tire flotation is the ability to remain on or near the soil surface as you are moving across that surface. Flotation is directly related to the weight and the footprint of the tires that are carrying that weight. The larger the footprint the better the flotation as well as the lighter the weight the better the flotation. When you are increasing the footprint and/or reducing the weight carried you are reducing the weight per square inch or down pressure. Reducing the weight per unit area reduces the ground pressure and reduces the compaction potential. Reducing compaction potential results in maximizing crop production.

How do you maximize flotation? Reduce the weight carried and maximize the footprints of your tires. Reducing the weight carried isn’t usually much of an option but maximizing the footprint is a very good tool that will reduce compaction.

Tire selection is really key to maximizing the footprint. Adding more tires, wider tires, the larger diameter tires, higher load carrying capacity tires, higher aspect ratio tires, ‘”IF” or increased flexion tires and “VF” or very high flexion tires can help achieve your goal. Adding more tires like front duals along with rear duals, triples or even quads can make a big difference.

The air chamber of your tires determines the weight carrying capacity for the most part so increasing the air chamber will increase your flotation. The larger the air chamber the more you can reduce your air pressures which are directly related to ground pressure. You can increase the size of your air chamber by increasing the width, height and aspect ratio. The higher the tires’ load carrying capacity the more you can reduce your inflation pressures. The higher the aspect ratio the more sidewall you have available for sidewall deflection to grow your footprint. The “IF” and “VF” tires carry about 20% and 40% more load respectively at the same air pressures or carry the same load at the respectively reduced air pressures.

The way to maximize your flotation is easy. Add more tire! Utilize very large diameter tires with large section widths, high aspect ratios, high load carrying capacities, coupled with the “VF” technology. The theory is solid, but implementation can be challenging without full understanding.

Ag tire traction is the transfer of power to the ground resulting in movement across the surface. To maximize traction you need to reduce tire slip.

Reducing tire slip can often be achieved by increasing ballast weight- opposite to the concept of reducing pressure to the soil via flotation. In most soil conditions; however, utilizing the higher load carrying capacity tires as well as the “IF” and “VF” tires will also increase your traction as the footprint architecture is altered in length and provides more in line tractive surfaces- while simultaneously improving flotation.

Flat Plate
There are really no industry standards for comparing footprints so be careful when using this information to compare between manufacturers. In general, using the flat plate or footprint calculations as a tool to increase flotation is quite easy. The larger the footprint the better the flotation. Utilizing the footprint to increase traction is not so clear cut. In some cases, the smaller the footprint the better the traction because you simply increase your weight per inch or per unit area.

In Sum
The biggest problem is wanting to maximize our traction to maximize our efficiency while minimizing compaction potential to keep from reducing crop yields. Flotation and traction are almost on a teetertotter. As flotation increases the traction decreases due to reduced ground pressures. As the flotation decreases the traction increases. These opposing effects are not so dramatic under low torque applications but can be quite extreme in high torque situations.

The best way to increase traction while minimizing compaction during high torque applications is to make sure correct air pressures are used for road and field speeds, increase the footprints in length via “IF”, “VF”, use higher load carrying capacity tires, along with higher aspect ratio tires with larger air chambers- this will grow your footprint in length providing optimum flotation, while at the same time lining up your tractive surfaces to provide the most efficient transfer of power to the ground!


GRI Tires
Rick Harris: Regional Sales Manager

Flotation is the tire’s ability to reduce the impact on field conditions, like soil compaction.

Traction is a tire’s capability of accomplishing work with fewer resources such as fuel, labor, time and mechanical wear and tear.

GRI XLR series works to increase traction with self-cleaning mud breakers, deeper than standard R-1W tread depth, and optimized carcass construction.

Radial tire technology increases traction and flotation simultaneously much like a drag slick at the start line; the tire’s sidewalls absorb the engine’s torque allowing the tread to remain in full contact with the ground and produce optimal traction.

The flat plate allows consumers to evaluate the contact patch of the tread at recommended inflation pressures.  A larger tread contact patch promotes increased traction and flotation.  A greater surface area reduces the amount of equipment and cargo weight supported by each section of the contact patch increasing flotation and mitigating soil compaction.


Dave Paulk: Manager Field Technical Services

Modern tractors are designed to transmit power from the engine to the ground. Transmitting that power requires moving traction to the soil surface. Traction determines how efficient this power is used. When the engine delivers too much power to the tires and friction to the soil is minimized, the tires will spin. Most modern medium to high horsepower tractors need weight added (ballast) to minimize wheel slip and maximize traction. The correct amount of ballast should be used to deliver enough traction for the power transmitted by the tractor without excessive wheel slippage. The needed weight is determined by the type of implements being used. Tractors can be weighted by cast weights or liquid in tires.  Traction is created by correctly utilizing the power of the tractor and the weight of the tractor to pull the required implements. Traction can be limited by wheel slip and rolling resistance. Traction can be increased by increasing weight and tire size or reducing air pressure.

Traction can be affected by air pressure, flotation, and the contact area with the soil. A greater contact area and less inflation pressure will generally increase traction. Traction is greatly enhanced by using the right size of tire for the tractor, the correct ballast for the tractor predicated on the implements used, and correct air pressures for the weight of the tractor. This also reduces soil compaction and saves money on fuel and time.

Flotation tires are designed to deliver maximum traction while minimizing soil compaction. They have wider footprints to distribute the weight of the tractor, combine, cart, or implement over a wider area of soil. Flotation tires can roll over loose or wet soil and minimize soil damage by not creating deep ruts. They can be used in free rolling or drive wheel applications and can carry a large amount of weight.  IF, VF, and IF-CFO/CHO technology has contributed to the versatility of flotation tires and allows them to be used in a variety of applications. Flotation tires are generally used on grain carts and wagons, combines, manure spreaders, and mixers.

The flat plate measurement of a tire is the contact area of the tire to the soil in square inches. The greater the contact area (flat plate measurement) of a tire footprint, the better the weight is distributed over the soil. Distributing the weight over a larger area reduces soil compaction and can increase traction. Row crop applications are limited to wider flat plate measurements by row width. If row width is not a concern, as in tillage or minimum tillage applications, a larger flat plate works well for traction.

There are basically four ways to manage traction efficiency and soil compaction. By managing the footprint of the tire, a farmer can increase traction and lower fuel costs. Managing the power of the tractor ensures that the tractor is weighted correctly, and the horsepower is efficiently used. Managing the ballast ensures the horsepower of the tractor is moved to the ground where it has the greatest value and is most efficiently used. Managing tire inflation pressure is using the right amount of air for the weight of the tractors and implements being used. Under inflation destroys tires. Over inflation can cause wheel spin and lost traction. It can also damage tires. Used with ballast, this is probably the largest contributor to maximum traction.

All these mentioned items work hand in hand to make a tractor (and equipment) efficient and deliver a good return on investment, with BKT producing a full range of farm tires and flotation tires to fit the needs of the modern farmer.


Michelin Ag
David Graden: Operational Market Manager – Agriculture

Traction and flotation are, and continue to be, confusing topics for many producers. In fact, with the addition of soil compaction, these topics are commonly the top three marketing and sales approaches for tier one Ag tire manufacturers today. At Michelin, however, solutions to these topics truly are our forte.

In sloppy soil conditions, there can be such a thing as too much flotation and not enough traction. On the other end of the spectrum, you can have too much traction and not enough flotation, which then gets into a situation resulting in major soil compaction. With the right tire, however, the chances of running into this can be slim to none. In fact, all Michelin Agriculture reps carry a set of scales and are equipped to handle the task of optimizing your machinery performance at any time.

To achieve the best of both traction and flotation, I would recommend a Michelin IF or VF tire, with our standard R1W lug, at the proper recommended air pressure. If your machine weight distribution and air pressures are set properly, there is little that can stand in your way of getting the job done. As an example, the image to the left here shows an S series combine outfitted with Michelin VF Cerexbib tires, working in sloppy wet conditions. The operator of this machine was so amazed with the performance he stopped his machine, took this picture and called his local Michelin Ag tire dealer to discuss.

To take it a step further, you could also use gross flat plate as a tool to determine which tire is best for you. Gross flat plate, or contact patch, is basically defined as the footprint a tire puts on the ground. Many manufacturers publish this information, however, Michelin does not. Unfortunately, gross flat plate is not governed by any office or institution and left up to the tire manufacturer to decide how that footprint is created. Therefore, this produces inaccurate results when comparing one brand of tire to another. At Michelin, we calculate gross flat plate differently between IF/VF tires and standard radial tires, for example.

When measuring gross flat plat for standard radial tires, the footprint area is measured at maximum load and pressure for a 20 mph (30 km/h) application. When measuring gross flat plate for IF/VF tires, however, we calculate for the tires max speed schedule at max load and corresponding air pressure.

Something else to keep in mind is that gross flat plate is not linear, which means the measurement at max load and pressure will not be the same at operating conditions. Additionally, Michelin calculates sidewall deflection. As you go down in pressure and load, so the increase in gross flat plat is exponential. Depending on the size and volume of the tire, the growth from max load and pressure to least load and pressure could be up to 30+% difference.

Getting to the point, the only way for one to know, for sure, how different manufacturers gross flat plates compare is to create an impression on a hard surface with the two tires at the same air pressure and load, then measure and compare the actual footprints- Michelin reps can help with this.

In sum, achieving optimum traction and flotation is achieved by choosing the right tire for the application, maximizing footprint (lugs on the ground) with IF / VF technology, and using correct air pressure in accordance with weight / speed.


Maxam Tire International
Greg W. Gilland:  Business Development & Ag Segment Manager

In any application that uses a pneumatic tire to act as the interface between the vehicle chassis and the ground, the key to successfully transmitting the force necessary to move in any direction is the application of the tire’s traction capability to deliver the torque or engine power, and the tire’s ability to float or carry the vehicle load at the necessary ground pressure to remain mobile.

Traction is the term used to explain how a tire overcomes the friction between the surface of the rubber tire and the ground. Friction is the resisting force that resists or acts against the relative motion of two surfaces. In other words, when a vehicle operates down the road, the vehicle engine generates the force or torque that push the vehicles wheels or tires forward and overcome the friction between the tire surface area and the road surface area. In summary, traction is the friction generated between the tire and the road or field surface.

Flotation is the ability of a tire to stay on the surface of soft ground, soil, or snow without rutting or digging into the surface or ground thus limiting the tire from overcoming the friction or providing traction. In agricultural applications, tires are designed to deliver the optimal traction or flotation based on their size, load capability and compounding. Ag tires are specifically sized to fit the wheelbase of vehicle chassis. Vehicle manufacturers choose the tire size that will provide their chassis design the optimal compromise between traction and flotation necessary for the tire to successfully overcome the surface friction to deliver the torque or mobility desired. In all cases, assuming the right tire size has been chosen, the key to delivering the best possible traction or force to overcome friction is the air pressure for a given load. When operating with a tractor in the field the coefficient of traction is measured by the “slip” of the tires as they roll through a field or road. Ag tires will use higher air pressure when operating on the road and lower air pressure when operating in the field. Here are some general rules that affect the ability of the tire to deliver traction:

If you work the field at the higher road inflation pressures:

  • You will have higher tire slip.
  • Tires will float less creating higher compaction.
  • You will experience higher fuel consumption.
  • Resulting in lower traction.
  • Reduced work rate.
    • Resulting in lower efficiency.

If you road the tractor at the lower field inflation pressures:

  • You will have less slip but higher rolling resistance or tire friction
  • You will have higher fuel consumption.
  • Your will have higher tire wear rate.
  • The tires will provide less ride comfort.
  • The tire will have less or lower lateral stability.
    • Resulting in lower efficiency.

In all cases, the optimum air pressure adjusted for the weight or load, and field condition (roading vs field work) will ensure that the tire delivers the best possible traction and flotation.

An Ag tire’s optimal air pressure also dictates how the tire construction or tread will provide improved or reduced flotation by extending or reducing the length of the tire footprint as provided below:

Tire traction is always improved when using the right air pressure for a given application. The vehicles slip meter will help the operator or grower determine the best possible air solution for their tires:

If tire slip is too high:

  • Check that tire inflations may be high.
  • Verify the load distribution from front to rear.
  • Add tire ballast or weights as required.
  • Optimize or adjust the working depth of any towed implement

If tire slip is too low:

  • Check that tire inflations may be too low.
  • Verify the load distribution from front to rear.
  • Remove tire ballast or weights as required.
  • Optimize or adjust the working depth of any towed implement


Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

Tires have been, and will continue be, the only link between farm equipment and the ground.  Farmers and equipment manufacturers continually face the dilemma of how to increase equipment efficiency while minimizing damage to the soil structure.

As equipment keeps getting bigger and heavier, the greater the concern of how this affects crop development.  As we know the heavier the equipment, the higher the soil compaction potential.  The amount of soil compaction is directly related to how much pressure is exerted into the ground.  Heavy loads, without properly distributing it, compacts the soil beneath.  Higher compaction reduces soil porosity that restricts root development and oxygen availability for plant growth.  The result is a smaller root system that explores less soil volume resulting in lower crop yields.  Some weeds like velvetleaf, bindweed, quack grass, mustards and horse nettle flourish in these conditions.

We would all like to have zero compaction, but zero compaction means zero traction because the equipment would not be in contact with the soil.

It’s time to introduce a complete list of terms required to make this subject easier to explain:

  • Footprint – this is the area that the tire contacts the ground. It is measured in square inches(in2).
  • Tire Load – this is the amount of weight, in pounds, the tire is supporting.
  • Ground Pressure – pressure is determined by dividing the tire load by the footprint. This is stated in lbs./in2.  Higher ground pressure results in higher soil compaction.
  • Flotation – is related to how much ground pressure is being applied by the tire. Tires with high flotation have lower ground pressures, and low flotation tires have higher ground pressures.

It’s a given that with a larger tire footprint, the ground pressure will be less, and compaction will be reduced (flotation).  Looking at this situation, the clear answer is to reduce soil compaction by putting the largest total footprint possible on the soil by using larger tires, taller tires, and/or more tires.  But where is the catch if the solution is that simple?

There is an inverse relation between flotation and traction, (i.e. higher the flotation the lower the traction, and vice versa).  So, there must always be a compromise when trying to maximize flotation and reduce ground pressure, and still be efficient in transmitting the power to the ground.  Inefficient power transmission (traction) from the tractor to the ground means increased slippage, increase fuel consumption and more time spent.  Excessive slippage accelerates the rate of tire wear and can also contribute to soil compaction.

Let’s start on how we can assure efficient power transmission.  There are some ground rules to follow that each equipment manufacturer promotes.  Depending on the piece of equipment we are working with, there is an optimal weight to horsepower ratio.  For example, a tractor pulling a heavy tillage implement would require between 100-120 lbs. of tractor weight per engine horsepower (a 400 hp tractor would need 40,000-48,000 lbs. of total weight).  The second step is to define the correct front to rear axles weight distribution, that not only depends on the tractor configuration (front assist or 4WD tractor) but also the effect of the implement pull on the drawbar.  This transfers additional load to the rear axle.  Once we have determined how much load is being carried by each axle, we can decide which size and number tires are required per axle to carry the load and allow efficient power transmission for the function of this tractor (tillage, planting, spraying etc.).

Simple right, we also need to take into consideration the restrictions the piece of equipment may already have on the size of tire that can be fitted.  Restrictions on how big the outside diameter of the tire can be and the maximum tire width for proper clearances with the fender/chassis.  The minimum rim diameter required to clear the axle, transmission and braking system.

At this point it is important to mention that the main tire component that carries most of the load is not part of the tire structure at all, but the air volume inside the tire. The taller the tire (higher ratio between width and sidewall height), or the wider the tire, the larger the air volume is inside the tire and the higher the load carrying capacity.

If we try installing tires with extreme flotation, we will lose the needed ground pressure for efficient power transmission, or traction, and will result in increased slippage that wastes fuel and time.  So, the question is, what is the limit on the largest size tire I can use to maximize flotation and minimize soil compaction?  The recommendation is to choose a size tire that:

  • First, fits your equipment.
  • Second, can carry the load, at a given air pressure, that is enough to carry the maximum load. To determine the carrying capacity of the tire, consult the tire manufacturer’s load/inflation data tables located in their technical manuals.
  • Third, the tire size meets the requirements of the field operation, row width, topology, soil conditions, etc.

It is possible to install too large of tires as the ground pressure will not be high enough for the lugs to sink into the soil and create the grip.

Also, even if the tire load/inflation table allows for it, do not use a tire with air pressure below the 10 psi threshold. Air pressure below this level may not exert enough pressure between the tire and rim to keep it from slipping on the rim.  Rim slippage increases the risk of damage to the tire when driving on uneven terrain (for example over a big rock) and each tire can lose a small amount of air as the tire flexes over time.  There is not a large enough gain in footprint when reducing the inflation pressure below the 10 psi to offset the risks.

One parameter that manufactures use to evaluate tire performance and how it flexes is the Flat Plate.  This value describes the area or footprint of the tire when its inflated to specified nominal inflation pressure load (following the Load Index LI of the tire).  This number is useful when comparing tires sizes and/or technologies from the same manufacturer since they use same testing methodology.  This published value represents only one situation (max inflation pressure at nominal load) and its difficult to extrapolate to each individual inflation pressure and load condition.  Also, different manufacturers measure this parameter in different ways so comparing data between manufactures can be problematic.


All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

Precision AG TIRE IMPACT 2019-11-05T01:36:49Z  

Michelin Ag
David Graden: Operational Market Manager – Agriculture

Precision Ag is very basically defined as satellite farming. It is the use of GPS and satellite imagery to manage machine routes, observe and treat crop problem areas, build crop and yield maps, and so much more.

Within Michelin Agriculture, I like to use these precision tools to prove tire value, conduct in-depth testing over long periods of time, and track machine operator habits.

From a tire value standpoint, I have successfully used downward force maps from high speed planters with overlaid yield maps. In the image shown here, this farmer allowed cattle to graze his fields in early spring every year. We discussed the potential issues surrounding the soil compaction impact, caused by cattle, can have on his overall yield. We blocked off one of his 4 fields from the cattle, measured the downward force it takes to plant the seed, then at the end of the season, we captured and overlaid yield maps. With this information, I was able to show the affect of about 9% yield gain as a result of less soil compaction. Additionally, this opened up a discussion regarding a test conducted by University of Illinois, where they were able to prove a 4.3% corn yield gain, using Michelin Ultraflex (VF) tires vs standard tires.

Regarding tire testing and machine operator habits, we often tie Michelin GPS equipment into the machine’s precision systems. This enables us to gather road speed and distances, field speed and distances, pitch and sway of the machine, stopping points, etc. With this information, we are able to research and create a value proposition, which is the starting point for Michelin to not only build new products, but also provide the very best tire for the application. Additionally, we can utilize this information when resolving tire issues and customer concerns.

Finally, as central tire inflation systems continue to grow in popularity here in North America, I see nothing but upward momentum. Precision Ag systems can feed an incredible amount of data, that will not only drive the machine, but the artificial intelligence required to run all aspects for total efficiency in machine operation in all seasons. With the late 2017 acquisitions of two tire inflation system companies, PTG and Telefow, Michelin has already realized and is rapidly preparing for this future.


Precision Inflation, LLC
Ken Brodbeck, VP of Technology

SMART Tires:

Today’s farm equipment utilizes GPS, variable rate planters, sprayers with individual row/section shut offs and self-adjusting combines.

Tires are now coming into the 21st century with variable technology to match.

Consider your new car or pickup.  Chances are they have a tire pressure monitoring device on your digital display.  They even tell you which tire is low.  Mine came on yesterday morning with the first frost.

Does your 8 tire $500,000 tractor tell you the tire pressure, individually?  Probably not.

What if we not only could check tire pressure, but automatically ADJUST the pressures for axle load, field vs. transport speeds and horsepower going through each tire?

This is where the industry is headed.

Today, Precision Inflation’s tire inflation systems require the operator to change tire pressures with the touch of a button.

In the future, the tractor will sense the load on the axle and change tire pressure automatically.  Ditto for field versus road pressure.  Lower for the field and higher for the road.

Michelin’s EvoBib tire is “Air System Ready” and specifically designed to change shape from the optimum lower field pressure to the higher road pressure.

Trelleborg is working on a combine tire system that adds pressure to the tire as the grain tank fills and releases air when the grain tank empties keeping the tire at its maximum footprint for best flotation and minimizing soil compaction.

Today, tires must be inflated for the worst-case condition which is usually transport speeds and loads.  But what if the machine is carrying only half of the maximum weight.  Think grain cart, sprayer, planter or combine.  In these conditions, the tires are over inflated for the load on the tire.  What if the tire/machine can sense the tire has only 50 or 70% of the maximum load?  The pressure can be reduced to match the actual load or speed the tire is experiencing.  Thus, optimizing the tire’s performance for traction, flotation, wear and fuel economy!

Today, the machine operator must know the load and speed for the tire to set the proper inflation pressure.  Soon, we will have SMART tires and machines that talk to each other and then adjust tire pressure for specific conditions rather than the maximum pressure for the heaviest load and highest speed.  No driver input required!


Alliance Tire Americas
Nick Phillippi: National Product Manager

Precision agriculture is all about using data to achieve exactness—it’s really focused on optimizing all the inputs possible to optimize yield. As a tire manufacturer, we utilize an extraordinary amount of precision in designing, engineering, creating and testing our tires. But once they’re in the field, the only variable farmers can really optimize on their tires is inflation pressure.

Fortunately, central tire inflation system (CTIS) technology helps tires become more of a precision input, because operating tires at the proper inflation pressure reduces soil compaction and improves traction, fuel economy, slip, rolling resistance and tire life. The ability to adjust inflation pressure from the cab is as big a revolution as the ability to adjust fertilizer rates or seed population on the go—and like those agronomic adjustments, reducing soil compaction by being able to lowering inflation pressure in the field can have a direct impact on yield potential and the bottom line.

There’s also a less-direct connection between precision agriculture and tires. If we can get access to the amazing stream of data being collected by today’s equipment, it could help us further improve tire design. Connecting inflation pressure data from a TPMS chip and correlating it with the data on slip and speed from a tractor, we could collect a massive volume of valuable, straight-from-the-field insight into tire performance. With that insight, we could build and test new designs with different variables and make the best real-world decisions.

Alliance has always worked closely with OEMs to develop new tires that help the machinery companies put their innovations into the field. Onboard data—the Big Data people talk about when they discuss precision agriculture—would help us be an even more effective partner with those OEMs.

Of course, just like farmers choose the right hybrids for a field and the precise fertilizer rates to maximize their yield potential, they can also choose the right tires for their operation. Selecting a tread design, ply rating/load index, construction—is this a good application for VF technology?—and size can have significant impacts on how the tires, the machinery and even the crops themselves perform. Factors can include soil types, whether fields tend to be wet or dry when the equipment would be in use, how much roading the machinery does, load, and other variables. Providing farmers with good choices is the driving force behind Alliance’s Whole Farm concept—we’ve developed low-inflation, low-compaction options for just about every wheel on the farm.


CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

Precision Ag encompasses the utilization of the latest technologies to maximize production on individual fields. There are many components that contribute to maximizing production as well as returns.

We start by reviewing each fields’ production history including  yields, quality as well as weed and disease problems.  Previous soil fertility information along with fertilizer applications and herbicide programs and efficacy need to be considered.  Crop rotation, projected market prices or contracts, pH, soil fertility, previous weed and disease pressure are the main components to evaluate to make the best planting decisions. After you have identified the crop you are going to plant you need to select the specific variety that works best for your conditions. You need to maximize production as well as evaluate what GMO traits are available and desired to produce the best crop possible.

After all the preparation work, you need to prepare for planting. Global Positioning Systems should be incorporated for all equipment operated in your fields. When using this guidance technology you are able to increase efficiency  by eliminating overlaps with tillage, fertilizer, herbicide and fungicide applications. You are able to get uniform row spacing as well as improved plant spacing that is key to maximizing yields. Soil sampling in a grid pattern so soil amendments as well as fertilizers can be applied as required in each grid to adjust the pH and fertility of the entire field to the same levels as much as possible. This is followed by GPS guided planting tractors that are dropping the appropriate number of seeds to that same grid pattern based on each grids’ yield potential. Scheduling in-season fertilizer, herbicide, insecticide and fungicide applications based on tissue testing, field scouting, and pest pressures are key to maximizing quality and yields while minimizing extra input costs. Incorporating yield monitors during harvest is critical to Precision Ag production efforts because you can record the yield consistency or inconsistency that you have achieved as a result of all of your efforts.

The need to maximize production and returns on each acre planted include all the Precision Ag tools and should include your Ag tire buying decisions. Soil compaction has detrimental effects on crop yields and needs to be managed as well as possible. The latest tire technologies include radial constructed tires as well as “IF”, “VF” and “IF CFO” advancements. All of these technologies enable a farmer to reduce compaction compared to bias constructed tires. The weight the tires carry is distributed over a larger footprint and has much more even weight distribution. Inflation pressures may also be reduced while carrying equivalent loads when the “IF” or increased deflection as well as the “VF” or very high deflection tires are incorporated into your Ag tire program. If you can decrease inflation pressures you are decreasing the compaction primarily by increasing the tire footprint. With these advanced technologies, you are also increasing traction compared to the bias construction tires. Increasing traction increases efficiency and also decreases compaction by reducing tire slip.

Do not forget to include the latest technological advancements in Ag tire design when you are making buying decisions for your farmers or for your farming operation.


Dave Paulk: Manager Field Technical Services

Precision agriculture is the application of using the right amount of water, fertilizer, pesticides, and herbicides at the right time to increase crop yields and protect the land. These practices can reduce the amount of each used and ensure that it is put in the right spots in a field to maximize yields. Farmers can gain a better return on their investment by saving on fuel, water, fertilizer, and pesticide costs.

Environmental concerns are also impacted by Precision Agricultural practices. Using the right amount of chemicals and fertilizer at the right times and in the right places helps crops grow better and healthier with better yields and reduces soil and groundwater pollution.

Precision Agriculture has been enhanced by using GPS and sensors to help find the right mix to get the most yield per acre of land. Emerging technologies include robots, self-driving/steering tractors, drones and satellite imagery, smartphone applications, machine learning, and the Internet of Things (IoT). The IoT consists of technologies for farm management software, animal welfare, and tracking almost anything related to helping on the farm.

At the onset, Precision Agriculture was very expensive and used only by larger farms. By nature, farms are land and labor intensive. Some of the costs of using Precision Ag have been driven down by using high-speed internet, mobile devices, and equipment designed for this by the tractor manufacturers.  This has made using Precision Ag practices somewhat more affordable to smaller farms.

The agricultural tires chosen to use in conjunction with these above-mentioned applications can be important.  By maintaining correct air pressures for the equipment used can decrease soil compaction and help increase yields. Soil compaction decreases the efficiency of water and nutrient absorption to the roots of the plant. Soil compaction also limits root growth and decreases yields. By managing soil compaction, the practices of Precision Agriculture and no till farming can be greatly enhanced by decreasing runoff.

IF and VF technologies used in agricultural tires can help with managing soil compaction. Pressure exerted by a tire on the soil is approximately two (2) pounds per square inch greater than the tire inflation pressure. If inflation pressure in a tire can be dropped and still carry the required weight of the tractor or implement, ground bearing pressure and soil compaction are reduced. When air pressures can be dropped, the tire flexes across a larger area and is able to spread the weight it is carrying more evenly.

An IF tire is designed to carry 20% more weight at the same air pressure as a standard tire. If air pressure can be dropped 20% and still carry the required weight, this would lessen the impact on the soil. BKT makes the Agrimax Force, some sizes in the Agrimax Teris, and radial implement tires in IF sizes.

A VF tire is designed to carry 40% more weight at the same air pressure as a standard tire. In this case, air pressure could be dropped 40% and carry the same weight as a standard tire. Some VF tires have been made for sprayers and implements where the weight carrying capacity is needed, and air pressures have not been able to be reduced. These include the Spargo for sprayers and some AW711 sizes for implements.  BKT has designed a VF tire, the V-Flecto, for agricultural applications where the air pressures can be reduced to take advantage of this technology.

Most large farms now use radial agricultural tires, but there are still a lot of bias tires used in the U.S. When shopping for tires with soil compaction and Precision Ag concerns at the forefront, radial tires are the way to go. Radials are designed to run at lower air pressures, where bias tires are not. Radials are designed to carry more weight and run at faster speeds. Radial ag tires compliment Precision Ag practices much better than bias Ag tires.

As agricultural equipment gets heavier and faster, tire technology must also improve to keep up with these advancements. The future will see more VF technology tires in a wide array of sizes and for a variety of applications. As farmers look for ways to decrease operating costs and improve profits, they will also have to look for ways to improve and protect their land. Tires can be viewed as another cost of doing business, or as an investment to help them reach their goals. With the right tires and good tire management, they become an investment to improve profits.

It is expected that by 2050, the world’s population will increase by 34% (to about 9.6 billion people) and food production levels will have to double to feed to feed everyone. It is important to start effective Precision Ag practices now in order to be able to sustain this goal.


Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

Precision Ag is the adoption of technology that increases the accuracy and reduces input needs. Basically, its objective is to increase the margin by increasing the yield and reducing the need for inputs. We can mention for example the use of less chemicals, faster tillage with less fuel usage, less compaction for better yields, input and yield monitoring. Tires have influence on several of these aspects as they are the link between the power of the equipment and how it’s transmitted to the ground. The correct setup of the equipment includes to setup correctly the inflation pressure of the tires. This process is mandated by the type of tire technology or where it will be working, the load that the tire must carry and at what speed this load will be carried.

The equipment manufacturer only releases tire sizes and configurations that “fit” to their products. If the equipment is correctly ballasted, the first step to adjust the tire inflation pressure is to weight the unit to the maximum load each tire must carry and at the desired speed. Using the tire manufacturer manuals, we can extrapolate the correct inflation pressure for the tire with the load and speed data. This optimal inflation pressure will adjust the tire to supply to the largest footprint possible, reduce soil compaction (increase yield) and increase grip with lower slippage (reduce working speed time and fuel consumption). Thus, you’ll improve driver’s comfort, tire performance and durability.

Following the idea that the tires need the correct inflation pressure to deliver their peak performance, several equipment manufacturers have been developing, testing and incorporating systems to monitor the inflation pressure in the tires (similar to cars) and displaying it on their monitors. This technology will be combined soon with tire self-inflating/deflating system to adjust to load and speed changes.

Using the tire at its optimal performance (with the correct inflation pressure) will assure that the tire will wear evenly and long lasting as the designed of tread life. Each tire manufacturer has developed and uses different rubber compounds in order to deliver the long-lasting peak performance. Each different rubber compound has its own “recipe” designed for a specific function and use. For example, a sidewall compound must be very flexible but dense, as the tread compound is stiffer and more heat resistant. This is a big differentiator between quality among the manufacturers (who performs better and last longer), and how they stand behind their products with support (warranty) and services.

In the last few years, the trend has been for the equipment manufacturers to develop larger units (heavier and bigger) equipped with more monitoring and adjusting capabilities. Following this trend, the tire manufacturers have been stepping up to the plate by offering tires with higher Load Capacities (LI), and specific tread designs for different applications. In addition to having features such as CHO-CFO for harvesting, IF-VF technology to increase load or reduce inflation pressure, larger sizes and new compounds have been developed to address the needs and demands of farming operation for a tire with flexibility and durability. Tire development is constantly evolving, and the industry is always incorporating new products to the market.


Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

I define Precision Ag as a farming management system based on the observation, measuring and responding to the constant variability of the soils and crops to optimize the efficiency of inputs like seed, herbicides and fertilizers to optimize crop yields which will optimize the returns on those crops produced.

Tires have always interacted with each facet of agriculture from spring tillage, spraying and planting to summer side dressing applications to combine, auger carts and tractors to fall tillage.  Each time a piece of equipment rolls across a field it is having a major impact on the soil in those areas and that is compaction. Growers have been concerned with compaction issues long before GPS and the term Precision Farming came around. So to me the tire industry has been keeping pace with the ever changing and wide variety of agricultural practices.

The major changes we have seen in the market is the sheer size of the tires themselves.  Back in the late 80’s early 90’s the standard tire on a 4WD tractor was a 480/80R42 then moved to the 480/80R46.  At that time one of the largest tires was the 710/70R38.  Fast forward to today, a 480/80R50 is the standard rear tire on a MFWD and we are putting on LSW1400/30R46 which is currently the world’s largest Ag tire on 4WD tractors.  The common theme being that as equipment has gotten larger and the capacity of the tires have needed to increase.  There are two ways to minimize ground bearing pressure which equates to compaction, and that is to physically increase the size of the tire itself or increase the size of the actual footprint on existing sizes. This is done by decreasing the inflation pressures of the current tires and in affect increasing the footprint distributing the load across a larger area decreasing the pounds per square inch (PSI) affecting the ground underneath and in turn reducing soil compaction.

There are many things a grower can do, for instance, IF (Increased Flexion) and VF (Very High Flexion) technology has been around for almost 15 years.  This technology allows you to reduce inflation pressures by 20% on the IF, and 40% on the VF which allows the tire to deflect more which increases the footprint area, with new equipment beginning to adapt.

LSW super single tires are also showing up on new equipment, with the tire not only substantially larger in size, but also incorporating VF technology, allowing the grower to gain an advantage for compaction just by bolting the assemblies on the machine by 20% and more.

Bottom line is that a grower can substantially reduce the effects of compaction just by understanding load and inflation when it comes to tires.  Many are surprised as to how low they could be running the tires on their equipment if they would just take the time.  Many growers just look at the sidewall of a tire and see that the tires max inflation is (example 1) 23 psi.  In this case the tire could carry 7,600 lbs.  However, what they don’t understand is if they run 23psi and only carrying 4080 lbs. they would lose almost 50% of their footprint. To carry the 4080 lbs. they would only need to run 9 psi.

Growers are not the only ones with little knowledge of this concept.  Many implement dealers, even larger ones that do have Precision Technicians know relatively little about load and inflation and almost nothing of IF and VF technology, yet the tires are a large factor in the precision farming arena whether they realize it or not.

Titan is very aware of this issue and holds the annual Titan University for that very reason in which we bring in not only growers and tire dealers but implement dealers as well.  They get a 2 day crash course on tires and tire technology so they feel more comfortable and understand how to optimize the performance of the machine and minimize impact on the soil. They soon realize there are many things they can do without spending a lot of money to improve their productivity and profitability.


Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

Precision AG has developed into a very wide field. In the beginning, it started with GPS steering systems and measuring and mapping yields, and it has become more and more complex over the past 20 years. Furthermore, fleet management systems have joined Precision AG solutions, so not only is data collected about yield, fertilizer, seeds, and pesticide optimization, but many machine parameters can also be monitored. Fuel levels, fuel consumption per time/acre and even data which can lead to machine downtime (such as temperature, oil pressure, oil level and failure codes) can be analyzed by farmers, fleet owners or machine service partners. The possibility of solutions seems nearly endless, so it´s difficult to describe them all in detail.

Looking at tires, two stages of development can be distinguished:

  1. Condition monitoring and corrective maintenance: tire maintenance and service checks (this is already quite common in the vehicle industry).
  2. The nearly endless field of possible intelligent solutions which improve productivity, efficiency and environmental protection for agricultural work.

For condition monitoring and corrective maintenance, Continental offers ContiPressureCheck as an aftermarket solution. This tire pressure monitoring system enables a single user to check and monitor tire inflation pressure and temperature either through an in-cab display or with a handheld tool. For a multi-vehicle solution, the ContiConnect platform can monitor an entire fleet of vehicles through the use of a yardreader. The ContiConnect platform has been very popular in truck and transportation businesses for years, and can also be used for agricultural tires.

For Precision AG, there are multiple possibilities where intelligent tires can improve safety, productivity and protect the environment by reducing future impact to the soil. Many of those possibilities reach their full potential by working together with solutions offered from agricultural machinery original equipment manufacturers. Close partnerships between agricultural machinery OE´s, their parts suppliers and tire producers are needed to make the possibilities a reality. In the future, these technological partnerships could lead to:

  • Optimal live tire pressure based on tire sensors and vehicle data (a tire inflation system is a pre-requisite).
  • Sensing deflection and deformation of a tire carcass in all three directions to give important steering values for tire load detection (for example, checking the filling grade of the fertilizer), tire specific force/torque (for anti-slip-regulation or preventing tire-rim-slip) and side deflection to identify critical situations by using reduced tire inflation pressure on steep inclines (to indicate how much tire inflation pressure can be reduced for inclines without creating the risk of falling over).
  • Measuring the tire contact patch to the soil online, to “feel” information about the soil condition that cannot be generated by an optical sensor (deformation, humidity). Then using this to adjust the tire to reach maximum performance and storing that information to yield maps.

These future technologies would ideally lead to fuel reduction, less soil compaction and better tire performance and lifetime. In addition, automation, digital solutions, secure data transfer, and efficiently managed material flows will enable operators of agricultural machinery and farms to individually configure their inventory and adapt it to meet their particular situations and needs. Agricultural enterprises will become state-of-the-art technology centers that promote efficient and sustainable production along the entire value chain. Continental’s cross-sector expertise assists in the further development of agricultural operations and providing new solutions, especially with reference to issues of relevance to the sector and its future, namely digitalization, connectivity and sustainability.


Maxam Tire International
Greg W. Gilland:  Business Development & Ag Segment Manager

Precision agriculture is a management approach to farming operations based on measuring, observing and actively handling all the possible variables in crop farming. Much like the advent of VF Technology, precision agriculture is incorporating every facet of technology to revolutionize how agricultural equipment operates in the field to maximize the yield of crops to ensure greater grower profits.

Precision ag demands the complete integration of all the field and crop production intelligence to include crop yields, terrain features, topography, organic matter content, moisture levels, nitrogen levels, etc., that can be gathered. Precision is achieved through the use of vehicle onboard systems or satellite technology designed to influence, for example, how a tractor and planter combination plant a field, how a harvester adjusts its header height to harvest more crop or, lastly, how the sprayer is used in terms of the correct spray pattern of fertilizer or pesticide when spraying a field based on all the above inputs.

In many ways, tires are the last element to be incorporated into precision agriculture as it’s not an integral mechanical or electrical component of the ag platform but rather part of the vehicle chassis as a mounted component. The key to successful implementation of tire technology in the field to maximize yields or influence precision agriculture lies in the active adjustment of tire air pressure when dynamically operating in the field or on the road. The tire’s air pressure not only carries the machine load but influences the size of the tire footprint (length) which has a direct impact on the ground contact pressure resulting in greater or lower compaction, ultimately, dictating the crop yield and the grower’s profits.

For precision agriculture to truly meet the objective of improving grower’s yields, the equipment in operation would have to fully integrate every aspect of the machine’s operation to include the tire impact. For example, in the case of tractor-planter operation, not only the best pattern of seed injection or seed planting depth for a given field, but also the tire’s footprint through the field by dynamically adjusting the air pressure up or down as the tires roll carrying the combined load. The on-board ability to maximize the exact and precise air pressure needed to minimize ground pressure or compaction will deliver increased crop yields and would maximize the capability envisioned in precision agriculture.

As heavier ag equipment continues to be developed in the years to come, on-board active tire inflation and deflation systems will allow either standard or VF tires to deliver the right footprint for the right load and ensure that precision ag delivers the right profit for each grower. A secondary effect of being able to adjust air pressures as needed at any time, whether in the field or while roading the equipment from place to place, is the maximization of the tire’s wear or longevity. Ultimately, tires that are employed effectively in every operation will last longer reducing tire usage and reducing operating costs.

Active precision agriculture, capable of adjusting tire air pressure in any field or road operation, will demand tires that are engineered to maximize the footprint resulting in reduced compaction and greater crop yields.  Future tire development is linked to VF Technology because of the flexibility in load carrying capacity or air pressure capability inherent in its carcass construction and rubber compounding.  Hence, MAXAM has engineered the VF agricultural series to provide the agricultural industry with the best tire solution for minimizing soil compaction without compromising traction, with the AgriXtra N being the first of many VF tire lines introduced to the global agricultural market beginning in 2020.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.


4WD Tractor TRACTION: Pulling 550 hp Implement 2019-09-14T03:57:48Z Below is question posed to tire manufacturers from Illinois:

  • In 4WD Tractor application, if implement requires 550 hp and standard duals are not providing adequate traction (can’t go wider with triples), what is your recommendation and how does it compare to tracks on transport & field speed?

Precision Inflation, LLC
Ken Brodbeck: VP of Technology

How to make your 4WD Tread Lightly and Pull Like a Locomotive!

An implement requiring 550 hp is definitely a heavy tillage requirement and demands the tractor be set up specifically for this high draw-bar application.

The tractor must have all three attributes properly set in order to provide comparable draw-bar pull to track machines:

  1. Tires:
    1. Base or standard tires may need to be up-sized to wider and higher load capacity tires
    2. Standard 620 or 710 width tires should be replaced with IF 800/70R38 for the widest and longest footprint possible
  1. Tractor Ballast:
    1. For heavy tillage, 4WD tractors require more ballast
    2. If 4WD wheel slip is over 8 to 10%, more ballast is required
    3. Typically, the rule of thumb is 105 lbs. per engine horsepower
    4. 550 hp x 105 lbs./HP = 57,750 lbs.
    5. Weight split should be 55% front and 45% rear for Ag Applications
    6. Front weight = 31,800 lbs.
    7. Rear weight = 26,000 lbs.
    8. Minimum PSI with IF 800/70R38 tires
      1. Front = 9 psi
      2. Rear = 6 psi
    9. If this is an extreme traction application, most tractors can be ballasted to 60,000 lbs. using the same 55/45 weight split
  1. Tire Pressure:
    1. Quite often the implement or tire dealer will over-inflate the original tires OR use the same smaller tire psi for the larger tires
    2. Over inflation shrinks the footprint and makes the tractor prone to power hop and higher wheel slip
    3. The tractor needs to be weighed on a scale or estimate weight using the tractor manufacturer ballast calculator to determine both front and rear axle loads
    4. Tire pressures then need to be set 1 to 3 psi above the minimum tire pressure unless the machine has a tire inflation system that allows the tires pressure to be maintained daily
  1. Speed:
    1. It is important to note transport speed differences between tires and rubber tracks with heavy hitch loads
    2. Often, rubber belt tractors have speed limits for weight and distance in transport. Tires do not have these limitations.  See rubber track machine advisory placard below:

Bottom Line:

Once you have completed the above 3 steps, the 4WD tire tractor will walk softly and run right with its rubber belted cousin with no problem- just like in the photo below!

And with a $100,000 lower price tag.


Jeff Staab: Product Line Manager – Track Systems

Farming equipment has become extremely specialized to respond to the numerous application requirements of today’s agricultural industry. For the high horsepower tractor range, original equipment manufacturers offer, direct from the factory, vehicles that are equipped with either tires or tracks. As machines keep getting bigger and faster and they pull larger implements, we’ve seen increased demand for tracks from the market. For end-users, the mobility of tracks in many applications remains a key differentiator.

Why Tracks to Increase Traction?

High horsepower tractors have to pull implements at various soil depths, in addition to completing multiple functions in a single pass in the field. Combine this with the need to complete these tasks at higher speeds and/or in as fewer passes as possible, tracks are helping farmers get the work done efficiently, especially when dealing with soft field conditions. In such conditions, performance is in the 1-5% slip range for tracked tractors due to longer and larger footprint, while duals will run in the 8-12% slip range. Slip reduction helps to maintain higher speeds in the field and to take advantage of the tractor and implements’ high performance.

Farmers appreciate the ride quality in the field with the tractor on tracks: they experience less vertical bouncing and no power hops. While they have to give up some ride comfort when roading, they like the narrower transport width going down the road, only 36 inches of track on each side of the tractor, making it more than four feet narrower than a tractor equipped with duals.


Maxam Tire International
Greg W. Gilland:  Business Development & Ag Segment Manager

Each agricultural operation requires equipment designed to maximize the pulling or transmission of a tractor’s horsepower (HP) to pull the desired implement through the field.

4WD tractors using tracks have the advantage of a constant footprint on the soil due to the length of the track and available contact footprint over the soil.

The larger the 4WD tractor (increased horsepower), the larger an implement the 4WD tractor can pull.

The options available for ag tires employed on larger 4WD tractors to transmit the machine horsepower, increase traction and ensure the required flotation (as compared to 4WD tracked tractors) are summarized below:


In the case of 4WD tractor applications, the choice of machine brand and horsepower available will dictate the options or size of tires that can be employed to deliver the traction expected to pull large implements.

Agricultural tires are designed based on their size geometry, materials and air chamber to carry a certain amount of weight at a given ground speed and to fit a certain wheel base or equipment.

In 4WD tractors the on-going challenge is to reduce the size or width of the tractor despite the fact, that with larger implements on the design board, more horsepower is being applied to all new 4WD tractors coming to the ag market. The below chart created by New Holland for the T9000 summarizes some of the width challenges and solutions offered by various tire options:

One solution, that has been tested with successful results, is to convert a tractor to a larger diameter VF Tire that simultaneously provides the tractor with reduced width solution, greater traction (tread length) and lower soil compaction (air pressure):

Provided below is a table comparing the above tires in terms of load carrying capacity in equivalent 4WD tractor applications based on tire specifications provided by both the Tire and Rim Association (TRA) and the European Tire and Rim Organization (ETRTO):

In summary, when challenged with a 550 HP tractor that needs greater pulling power at reduced widths (no triples – less than 14 feet) convert your tractor to larger diameter tires that can be used in duals giving you greater traction, footprint and reduced machine width. VF Technology continues to bring new solutions that are re-defining the use of tires to meet the growing challenge of larger, more powerful tractors.

When you compare the advantages of tires to tracks, tires are easier to maintain both in terms of mounting, impact of tracks on overall machine weight, vehicle maintenance and the overall fuel efficiency of the tractor. Machine speed and fuel consumption will be based on the load the machine is pulling either in the field or on the road whether with tracks or on tires.

Maxam Tire is actively working to develop VF Technology ag tires to meet the evolving and increasing weight demand of the next generation of ag equipment, with our first VF tire solution being our Agrixtra N (N for narrow) high clearance sprayer VF 380/90R46, with 4WD tractor VF technology coming to market over the next few years.


CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

John Deere 9620R Example

The first thing to do is determine the actual gross weight per axle. The Base weight of this tractor model is 43,420# and the engine horsepower is rated from 370 to 620 hp. We have to assume we have the 620hp engine.

The minimum recommended gross weight should be 62,000# with 60% of the weight on the front axle and 40% on the rear. You need to add a minimum of 18,580# of additional weight via suitcase, axle or wheel weights. If adding weights does not accomplish the gross weights or weight distribution, you can add weight via liquid ballast.

Check your inflation pressures on all tires. Normal inflation pressures for this setup would be 10psi in the front and 8psi for the rear tires.  You may be able to lower your inflation pressures but you need to consult the tire manufacturers’ load and inflation tables before you do this. If the gross weight and the distribution is correct and traction is still an issue you should add additional weight approaching a gross weight of 74,400# with the appropriate distribution. This additional weight gets you to 120#\ hp.

We have no information concerning additional weight to the drawbar that would be exerted by our implement so minimal consideration will be calculated into our recommendations.

In Sum
Setting up this tractor with the gross weight at 120#\hp with the correct distribution and correct inflation pressures should provide more than adequate traction.

If that is not the case, another option to consider would be renting or borrowing a smaller implement that has lower power requirements. If this situation is a normal, regular operation you might consider replacing your tires with IF or VF type tires that will provide longer footprints, increased flotation, and increased traction.


Dave Paulk: Manager Field Technical Services

Managing traction is important to controlling costs and efficiencies on a farm. Too much tire slippage can increase fuel and labor costs. The more lugs that can be put on the ground, the better the traction and performance will be. When high horsepower tractors are used with heavy implements, higher air pressures may be required to support the increased weight. Higher air pressures in standard rated tires can lead to less traction, more tire slippage, and a greater increase in soil compaction. Having the ability to reduce air pressures without damaging the tire will give a larger tire footprint and better traction.

Tires with IF and VF technology may help with traction and lead to less tire slippage and better flotation. IF tires are rated to carry 20% more weight at the same air pressures as a standard tire. VF rated tires are rated to carry 40% more weight at the same air pressures as standard tires. If a tire can carry the same weight at 20% to 40% less air pressure respectively, this allows for a larger (wider) tire foot print with more of the tire and lugs on the ground for traction. This allows less slippage and fuel savings. Tires provide better traction as their inflation pressures are decreased. IF and VF tires enable a tractor to carry more weight on the road without having to widen the tractor with triples. They can be used to minimize soil compaction where important. Looking at these tires to replace standard rated tires would be a first step in solving this problem.

When comparing tires with tracks for traction, there are pros and cons with both. Tracks provide more traction and flotation in wet soil and tracks have a longer foot- print. Tracks generally work with less slippage, about 5% compared to 8-15% for tractors. This should give tracks the advantage of pulling heavy equipment where triples can’t be used. Field speeds with tracks should be equal to, and maybe a little better, for tracks in this proposed application.

Often times, farms are scattered, and tractors must be transported on the highway. Pneumatic tires work better with this application.  Another question is the cost of operating a tractor with tires vs. tracks.  The cost of maintaining the suspension on a tractor with tracks is expensive compared to that of a tractor with tires. On a tractor with tires, you basically only have to worry about tires, wheels, and hubs. Tracks are more expensive than tires and there are many more moving parts on a tractor with tracks.

As a comparison, if tires can be used and give the required traction, they are much less expensive to maintain. They ride and handle better, and generally last longer than tracks in highway use.  While there advantages for tracks, the farmer must decide what is best for his application and what costs he can live with.


Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

Every farmer strives for the highest efficiency on power and torque transfer from his tractor to the ground. He seeks the lowest slippage, lowest fuel consumption, lowest compaction, and fastest speed possible. Not all conditions can be achieved, yet many combinations can be applied to meet proper needs. Each element must be approached step-by-step.


First, we consider the transfer of power to the ground. It begins with balancing the total tractor weight and its power (as the weight distribution depends on tractor power). There are general rules to follow when determining this balance. Heavy tillage must consider between 100 to 120 pounds per tractor engine horsepower. In this case, a 620 hp tractor would need between 62.000 to 75.000 pounds of total tractor weight. As for weight distribution between front and rear axle, it will depend on how much down force the implement applies to the rear axle. Broadly speaking, a starting point of 55% front-45% rear and up to 60% front-40% rear is the right point.

Inflation Pressure

Secondly, focus on how to transmit power to the ground. A track system does not require any adjustments; but remember that the rubber track must be tensioned well, to avoid slippage on the wheel. Tires, on the other hand, must be adjusted; to monitor inflation pressure (per the tire manufacturer recommendations). Once the correct weight for the tractor has been established, we may define the correct inflation pressure, depending at what speed we intendent to drive the tractor.


On conventional tires, (not IF or VF technology) the load capacity increases when we reduce the working speed (at same inflation pressure). That being said, it is very important to be aware of the machine’s speed that the tractor-implement will be working. Follow the tire manufacturer recommendations to assure the tire footprint is the largest possible for the load; with more lugs on the ground for traction and larger footprint for lower compaction. One point to consider, while using dual fitment, is that the load capacity is reduced by 12% on each tire –meaning that the load capacity should not be doubled. By adding duals, you gain 1.76 times the single load capacity. The reduction is even higher when using triples. Each tire load capacity is reduced by 20%, conveying a triple set will carry 2.4 time the load of a single tire (not 3 times).

IF /VF Tires

On IF and VF technology tires, there is no gain in load capacity when speed is altered. Once the load has been established, the inflation pressure may be determined. The advantage of IF and VF technology tires is that they can carry more load at the same inflation and inflation pressure can be reduced with the same load. A lower inflation pressure means more lugs on the ground and larger footprint with lower compaction. An important point to mention is: there is an opposite relation between traction and flotation. When flotation is increased (for extreme compaction) the lug pressure is reduced on the ground (less traction), and slippage increases. Each farmer will have to find the right compromise between power transfer efficiency (less slippage) and compaction (flotation).


With a better understanding of setting up tires on a tractor, we can now discuss solutions to when the tractor does not perform as expected. If there is excessive slippage, it may be because of the following two main reasons. First—too much pull from the implement (meaning the implement requires more power as the tractor can deliver). Or, the tires are not transmitting the power to the ground.

In the first case, the only option is to reduce the implement power needs (for example: reduce the implement penetration) or reduce the working speed. It is also possible that the soil conditions are not normal-optimal for the operation (such as: too wet). Resulting in more power as in normal conditions. In this case, the farmer would need to schedule the work for a better soil condition if possible.

For the second reason, the farmer would need to check first that the inflation pressure is correct (as per tire manufacturer recommendations) for the tractor weight. If correct, and there is no possibility to add triple tires- additional weight may be added (if not yet at the maximum weight allowed). Or the tires may be changed to provide a larger and wider footprint and ensure they are R-1W tread (20% deeper lug height as R1 tires) or the lug design (45-degree lugs, Progressive Traction technology). Also, it is possible to change to IF or VF technology, allowing the reduction of inflation pressure and increase the footprint (more lugs “biting” the soil). This usually requires a change in rims (VF technology uses wider rims).

In most situations, a correct tractor weight and distribution (actual tractor weight – not the manuals estimated weight), with the correspondent tire inflation pressure is enough for an efficient performance. Remember to always consult your trusted tire dealers or equipment dealer for additional information.


Alliance Tire Americas
Nick Phillippi: National Product Manager

With massive loads and high horsepower, today’s top-of-the-line tractors are placing huge demands on tires. There are three levels of commitment an operator can undertake when it comes to maximizing the performance of the tires and the equipment: managing the inflation pressure properly (easiest), switching to low-pressure tires (moderate), and, ideally, using a central tire inflation system to maintain optimum pressure (fully committed).

In tires, it’s all about inflation pressure. With a massive tire like an 800/70R38, the difference between 23 psi (which many farmers will inflate to because it’s easy and going to the max seems like the safe choice) and 12 psi (which is optimum for field work) is night and day. Just dropping to that lower inflation pressure is enough to transform his tractor into something he didn’t even know he had.

And all it takes is an air gauge, a tire inflation chart and a few minutes to really get the most out of that $400,000 he invested in his tractor.

The next step, especially with a huge tractor, is switching to VF tires. It is possible to “over-tire” some tractors, as Dallas Ransom discussed in a recent blog. But with a John Deere 9620 or a Steiger 620, you’re talking about 50,000 pounds of machine. Nobody makes a tire too big for that.

With that kind of load, VF tires will pay off all day long, especially because you can handle the same load as a conventional radial with 40 percent less inflation pressure. That allows you to get down as far as 8 or even 6 psi and really give tracks a run for their money in terms of traction and flotation.

Of course, the best way to get duals to maximize traction is to lower inflation pressure in the field and only raise it on the road. Under those conditions, the tires should perform equivalently to tracks at all times—while being a lot less expensive and much easier to maintain.

As much as we in the tire industry would love to see farmers stop on the edge of the field to adjust their inflation pressure, the most practical way to ensure that the adjustments are made would be to install a central tire inflation system (CTIS) on their tractor, especially if he or she has made the investment in VF tires.

CTIS technology allows the operator to adjust inflation pressure with an onboard compressor at the touch of a button. In just a couple of minutes, a set of tires can be adjusted to optimum inflation pressure for either field or pavement, low speed or high. CTIS can be easily retrofitted onto tractors, and can cost less than a set of tires. Especially if a farmer is investing in IF or VF tires, CTIS is a great complement to that.

With all the advantages of CTIS—including better traction, improved flotation, more effective transmittal of horsepower to the ground, increased fuel economy and longer service life from your top-dollar tires—investing in the technology begins to return immediately and a good system can pay for itself very quickly.


Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

The key to any high draft load / heavy tillage applications requires three things.

First, the tractor must be ballasted heavy enough to pin the power to the ground.  As discussed in previous articles we recommend 90lbs to 120lbs per horse power as a guideline for total machine weight.  Additional ballast may need to be added to achieve the proper machine weight.

Secondly, along with total weight,  front to rear weight distribution is also critical.  We recommend a 60/40 (front/rear) weight split as a target.

Lastly, once the tractor is ballasted correctly inflation pressure must be set for optimal performance.

Below is an example of loads and inflation which would work on any model tractor:

600+ HP Tractor (Any Brand) Ballast and Inflation Recommendation

Total Machine Weight    62,000 lbs.

Front Axle Weight            37,200 lbs. (9300 lbs./tire)

Rear Axle Weight             24,800 lbs. (6200 lbs./tire)

Recommended Inflation

710 (Duals) Rear Front 800 (Duals) Rear Front 900 (Duals)
710/70R42 9psi 16psi 800/70R38 6psi 13psi LSW900/50R46 6psi 7psi
IF710/70R42 6psi 12psi IF800/70R38 6psi 9psi
VF710/70R42 6psi 9psi VF800/70R38 6psi 7psi
LSW710/60R46 6psi 12psi LSW800/55R46 6psi 9psi
LSW1100/45R46 12psi* 17psi
LSW1250/35R46 12psi* 17psi
LSW1400/30R46 12psi* 17psi

*VF agricultural tires when used as singles minimum 12psi (TRA standard)

Tracks machines are different in the fact that they typically sit at or close to the appropriate weight without hanging another piece of iron on the machine.  The down side is that the machine cannot be made any lighter when a lighter less compaction type application is being performed such as planting.

Road transport speeds and distance in track machines are typically reduced due to the wear and tear on the tracks themselves.

In the field I would put up any LSW tire on a wheeled machine against any track machine of similar horsepower and run toe to toe with the track machine.  I have seen time and time again conventional tires tend to not perform as well as tracks or LSW tires due to the propensity to power hop in the field causing the tractor to loose tractive efficiency and therefore being less productive across the field.

Road speeds are also typically higher in LSW equipped machines versus track machines or machines equipped with conventional tires due to road loping issues.  Titan/Goodyear offers expertise in the field with our Ag Specialist Team, with the group’s sole purpose to assist end users with application issues- they will come out and scale equipment and make recommendations on ballast and inflation to ensure optimum performance.


Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

As a broad portfolio provider, Continental offers both rubber track and tires for a complete agriculture solution. There are certain applications where each excels and is a better overall fit for the needs of the operation. Farmers should consider investment and maintenance costs, road driving capabilities, transportation width, soil compaction, traction and fuel consumption. To help customers make the right equipment choice, Continental has a team of experienced field engineers who visit and consult with customers in the field. Every application is different, and Continental offers products to meet every need.

Both track and tires can provide superior performance, depending upon the application.

The benefits of  TRACK include:

– Narrower transport width for the same load capacity
– More pulling traction in wet conditions
– Less fuel consumption per acre at high loads and high torques
– Less track width, able to handle row applications in wet and muddy conditions with narrow tracks
– Same footprint area on less track width means less soil deformation energy in total
– No time required to adjust tire inflation pressure
– Less slip rates to transfer the pulling force
– Soil protection, if highest loads needs to be carried (where tires need high inflation pressure)

The benefits of TIRES include:

– Lower investment cost
– Lower vehicle weight
– Lower fuel consumption per acre for lower torque applications, as tracks have more moving parts
– Less heat generation at road speeds
– Lower maintenance costs
– Reduced soil disturbance on end row
– Improved steering on steep inclines
– Uniform soil pressure distribution
– Better ride

Continental heavy-duty farm tires are versatile for applications that need performance in the field and on the road. They have low heat buildup while roading and can be driven loaded and unloaded on both roads and fields. Tires offer low investment and maintenance costs, uniformly distribute soil pressure and are efficient for road transportation. To optimize traction, farmers should reduce the tire pressure to the recommendation stated on technical data sheets. Oftentimes, the inflation pressure is too high creating a smaller contact patch of the tire to the ground which lowers traction.

For an application with full power field work where standard duals are not providing adequate traction and the user isn’t able to go wider with triples, track offers an efficient solution. Continental Trackman rubber track, constructed for the most severe and extreme applications, are able to transfer more torque to the ground and gain greater traction, all with high flotation because of their larger foot-print. This foot-print allows the machine/equipment weight to be distributed across a greater area and lowers the ground pressure, without increasing width as triples would require. Reducing ground compaction equals greater crop yields.

In order to get the power to the ground with the highest horsepower equipment in the marketplace, we recommend market leading guide-lug support system called ARMORLUG®, MAXXTUFF™ wire ply construction providing more ends per inch, and now the patented ARMORLUG® ULTRA that provides 25% more torque capability than before.


Michelin Ag
David Graden: Operational Market Manager – Agriculture

As a producer, you are inundated with marketing campaigns, ads, salespeople feeding you opinions as fact, etc. The truth is, if you know what you want to achieve and you know what is available, it will lead you to the decision that meets your needs.

At Michelin, we begin with creating tires based upon a farmer’s value and needs. From there, we teach our sales reps to find the facts and match the right tire based upon those facts. Finally, we close the loop by proving lower total cost of ownership and stand behind our decision by working with you year after year.

In the case of a 4WD machine, pulling an implement that requires 550 hp, there are several cost-effective tire options for you that can do the job. First, begin with listing your needs:

  1. Traction
  2. Torque transfer
  3. Limited width (triples too wide)
  4. Are you concerned with fuel economy?
  5. Do you have the need to travel between fields at a descent rate of speed?
  6. Have you considered soil compaction and the proven effects on yield?
  7. Have you looked at the different machines and price gaps between each?

Typical tire sizes found on these machines are the 710/70R42 and the 800/70R38. I would recommend going with the VF (Very High Flexion) tires in these sizes in the new Axiobib 2 or Evobib. Each of these tires has been extensively tested and marked with “Inflation Systems Ready” on the sidewall, meaning they are designed to optimize your tire pressures based upon your needs- with the simple push of a button.

Let’s take a look at the air pressures required to transfer 550 hp. When calculating the optimum tire pressures, we need to first know what the machine weighs and calculate the proper weight distribution required to transfer that torque to the ground.

At 6 mph, these machines will require about 95 lbs. per engine horsepower. That comes to 52,250 lbs. total. Next, you want about 55% of that weight on the front and 45% on the rear axles. This weight distribution will eliminate power hop and road loping.

For each of these tires, the front axle air pressure for field operation is 9 psi and the rear axle air pressure for field operation is 6 psi. With a PTG central tire inflation system, for roading, you can then increase the air pressure to maximum psi on the sidewall for each tire and travel at maximum machine speed!

The main difference between these two tires is the Evobib will have a much larger footprint at 6 and 9 psi than the Axiobib 2. Due to the shoulder design of Evobib, the footprint of this tire will actually increase by over 28 additional pairs of lugs on the ground at field operation pressures!

So, in addition to transferring 550 hp to the ground, you want higher road speeds, less fuel consumption, increased yields, and an overall lower cost of ownership, our recommendation is to pair a premium VF tire with a central tire inflation system.


Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

When users complain about traction in the field, the first thing that needs to be done is make sure the tractor is set up correctly. Loss of traction could be due to under- or over-ballasting of the tractor, too high of inflation pressure in the tires, or using liquid ballast in the tires. Before we recommend different tire sizes, tire technologies or mobile solutions, let’s get the tractor set up correctly.

For a 4WD tractor, the target ballast weight is 110 lbs per engine horsepower in heavy drawbar pull.  A 620 hp 4WD tractor should have a base weight of 68,200 lbs.  The weight needs to be distributed so that 51% – 55% is on the front axle, and 45% – 49% is on the rear axle. The front-axle target weight would be between 34,782 lbs and 37,510 lbs, and the rear weight would be between 33,418 lbs and 30,690 lbs. I recommend using steel ballast to obtain the weight on the tractor. Using liquid ballast does not damage the tire, but liquid does not compress. Since liquid does not compress, it will prevent the sidewalls from properly deflecting, and will make the tire stiffer. This extra stiffness causes the tire from developing a full footprint, reducing traction in the field. By using the ballast calculator provided by the tractor manufacturer, the machine can be ballasted with the available steel weight package, which provides a front-axle weight of 35,500 lbs (52%) and a rear axle weight of 32,700 lbs (48%).

With the front- and rear-axle weights set to utilize the engine horsepower, the minimum inflation pressure for the tires can be calculated. Assuming the tractor has dual 710/70R42 tires, the minimum inflation pressure needed to carry 35,500 lbs on the front axle is 20 psi. The minimum inflation pressure needed to carry 32,700 lbs on the rear axle is 17 psi. Setting the pressure to these weights allows the tires to develop the largest footprint possible. The pressure in the tires also determines what the ground contact pressure is. In this setup, the ground contact pressure is approximately 22 psi on the front axle and 17 psi on the rear axle.

If the tractor is set up correctly, and it still does not seem to have the required traction (excess tire slippage on firm soil), then it is time to look at the IF or VF tires. IF and VF tires allow the tires to carry the same axle loads at lower inflation pressures. The lower inflation pressures allow the tire to deflect more, allowing the footprint to increase in length. The longer footprint allows more tread bars to make contact with the soil, increasing traction. For a 620 hp tractor, Table 1 shows what inflation pressures are needed to carry the axle load:

Table 1: Minimum Inflation Pressure

The benefit of the IF and VF tires to the user is that the standard radial tires can be replaced with the IF or VF tires, with only an investment in the tires. The Firestone IF and VF tires are approved to go on the same rims as the standard radials, making extra spending on wheels or different mounting hardware unnecessary. The lower inflation pressure increases the footprint area, and provides an improvement in traction and a reduction in fuel usage. The lower inflation pressure also reduces soil contact pressure, helping to limit soil compaction.

When comparing four-track systems to wheel setups, it’s important to understand what performance targets are important for the operation. Both setups provide users with various benefits. Wheeled tractors have a lower initial purchase price and lower operation cost. When the wheel tractor is set up with tires that allow for inflation pressures below 15 psi, the wheel tractor will have lower soil contact pressure versus a tracked tractor. In wet soils, a tracked tractor provided better traction performance, because the track acts like a road paver. As the tread of the track engages the soil, it stays in the same position, and the undercarriage moves forward. That is why a tracked tractor does not seem to rut the field up in wet conditions. On a wheeled tractor, the tire is continuously rotating, and in wet soils, the tire pushes the soil, causing ruts.

It doesn’t matter whether a 620 hp tractor has tires or tracks; if the tractor does not seem to have the proper traction in the field, the first step is always to make sure the tractor is ballasted correctly. After the ballast has been corrected on wheeled machines, make sure the inflation pressure is set to match the axle loads; and on tracked machines, make sure the undercarriage tension pressures are correct. If more traction is needed on a wheeled tractor, IF and VF tires will provide a larger footprint, which generates more traction in the field, and could be a lower-cost solution versus purchasing a tracked machine. If the machine is going to be used in wet conditions, a tracked machine may be a better option, but remember that the track machine is still compacting the soil.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

Best Load Speed Index 2019-07-02T13:06:21Z How does producer choose best Load Speed Index, what is impact of IF / VF, and how does change from transport speed to in field affect air pressure requirements?

Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

Starting with the simplest component: Speed Symbol (SSY). The Speed Symbol is the maximum speed the tire is designed for. It correlates with Load Index as a STANDARD TIRE can carry even more if the speed is lower. For Agriculture Radial Tires, the most common Speed Symbols are A8/25mph, B/31 mph, and D/40 mph. If your tractor runs faster than 25 mph, you will need the B or D rating. If your tractor is 25 mph or lower, A8 is fine.


A little more complicated is the Load Index (LI): it is always related to a certain speed and to the (nominal) inflation pressure.

Here’s a practical example for a 710/70 R42:

The tire is rated with 173 D, so it can carry 14,330 lbs at 40 mph.

If you have a tractor with a max speed of 25 mph, the load can be increased going down three SSY (D=>C=>B=>A8).

This allows you to increase the LI three steps meaning the 173 D tire becomes a 176 A8 tire and can now carry 15,652 lbs at 25 mph.

The third influence on standard tires is the inflation pressure. Higher inflation pressure means higher load capacity. Therefore, the maximum LI and SSY are always given at the maximum allowed inflation pressure at maximum speed, called nominal pressure.

A farmer who is aware of the soil and its effect on plants, should choose a tire by its ability to be operated with low inflation pressure on the field instead of looking at the maximum LI and SSY for road conditions.

As shown above, the contact patch is directly affected by tire load and the inflation pressure. Adding load to the tire will increase the contact patch, while the pressure stays constant in this model. But also keeping the load constant and reducing the inflation pressure for in field will increase the contact patch.

In short, to run a STANDARD tire at maximum speed with a high load on-road requires a significantly higher inflation pressure, while you can reduce the inflation pressure at on-field speeds to protect the soil. All these pressure changes require technical solutions like an air pressure kit in the field, so a new tire model was evaluated.


The first step was the IF, and the second evolutionary step is the VF tire, taking out the need to change air pressure between field and road speeds at constant load and ~20% more load for the maximum specified speed for IF and ~40% more load at maximum speed point for VF at the same inflation pressure compared to a standard tire.


The higher price for VF tires can be a good investment for farmers and contractors who change between field and fast road work often, as no pressure adjustment is needed for the different speeds with constant loads. VF enables you to ride up to the highest speeds with the lowest inflation pressures.


Precision Inflation, LLC
Ken Brodbeck, VP of Technology

First, be sure to have a speed rating that meets or exceeds the maximum speed of your machine.  Most radial tires are at least A8 (25 mph) or B (30 mph).  Newer technology tires are D (40 mph).

Next, be sure to have a load index that meets or exceeds the maximum weight requirements of your machine configured with implement you have chosen.

Your tire dealer and the major tire manufacturers list these values in their data books and online.  Now let me explain each term with an example.

Load Index: is a table of maximum load values that are standardized by the tire manufacturers.

Speed Index: is a table showing the maximum speed allowed for the tire.

The speed index is usually stamped on the tire sidewall right after the Load Index number.

How do Standard (St.), (IF) and (VF) tires compare at two different axle loads?


  1. Without CTIS (Central Tire Inflation System), you have to run transport psi all the time
  2. IF and VF tires allow lower pressures of 19 and 16 psi respectively.
  3. WITH CTIS, a standard tire can be set for 14 psi in the field and 26+ psi on the road!
  4. Bottom line, often a standard tire with a CTIS can outperform the higher dollar IF and VF tires without an inflation system. See the above chart.

Inflation system technology also improves the performance of IF and VF tires.  In fact, every radial tire works better with CTIS to optimize and maximize the performance of your farm equipment.


Michelin Ag
David Graden: Operational Market Manager – Agriculture

On the sidewall you will find a load speed index expressed like this: 167B.

  • The first three numbers are the load indices or weight a tire can carry.
  • A8, B, or D indicates the speed rating of the tire.

Both weight carrying capacity and speed requirements must be assessed to choose the proper load speed index.

When determining speed requirements, I recommend both in field and transport maximums are determined.  Knowing physics enables a standard tire to carry load with significantly less air pressure at slower speeds, this is very important if you are concerned with reducing soil compaction.

For example, an 800/70R38 MachXBib carrying Max Load of 14,330 lbs. at 23 psi at 40 mph (transport) can carry same weight at 6 mph (field) with 15 psi.

Reducing pressure 8 psi over 5,000 acres equates to a significant improvement in a grower’s bottom line.

So how do you (real world) change air pressure from road transport to field quickly at crunch time?  Use a CTIS system.

Do you want to take air pressure savings to another level? IF / VF tires that can do even more.

In sum, determine required weight carrying capacity, determine in field and road transport speeds, and then I recommend investing in a Central Tire Inflation system.  To really maximize yield, go VF.


Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

Load and speed index symbols are a little bit mysterious. The numbers—like 129, 141, 151—look arbitrary, and the use of stars or letter/number combinations like A8 to indicate load doesn’t feel very precise. But the most important aspect of load and speed index is that you know that they exist, and you make sure to match them to your needs when you purchase new tires.

Mysterious or not, load and speed index represent vital information. If you buy a tire with too low a load/speed index to cover your needs, you could overload your tire. That can lead to premature wear, accidents and spills, or even injury or death. I can’t say this too many times: you need to match the load and speed index of your tires to the machinery they will be running on.

Be sure to calculate your need for load and speed based on the real-world weight of each axle on your machine. That means you have to look beyond the machine’s shipping weight to also account for the weight of fuel, spray solution, ballast, and load on the drawbar. If it’s got a bucket on the front, add the weight of a full load of dirt or gravel. Be real about what you’re going to be doing with that machine and you will end up with an accurate load index.

The same goes for speed. The low speeds of planting or fieldwork can be accomplished at a lower inflation pressure than higher-speed road driving. If you’re going to operate a farm tire at higher speed, check your inflation tables to match the load, speed and optimum inflation pressure. If your pressure is too low for your load and speed, your sidewalls will flex too much and build up extra heat, which can result in excessive stress on the tire carcass and ultimately could destroy your tire.

That’s where IF and VF technology come in. The special design and materials in IF and VF sidewalls allow us to operate these high-tech tires at lower inflation pressure without giving up load and speed. In fact, the load rating of an IF tire at a particular inflation pressure is 20% higher than the load rating of a standard radial at the same pressure. With VF tires, the bonus load capacity is 40%.

To get the full benefit of IF or VF technology, check the inflation tables and make sure you run at the proper pressure for the load and speed that reflect your operating conditions.

And to really stay in step with load/speed index and optimum tire performance, central tire inflation system (CTIS) is the ultimate tool. Linking a compressor to each tire on the machine for on-the-go pressure adjustments, CTIS technology—used by the US military since the mid-’80s—is surprisingly affordable and allows you to increase inflation pressure to run safely on the road and decrease it for better performance and lower soil compaction in the field.

The nomenclature of load and speed index may be mysterious, but the answer to all the mysteries is right there on the inflation tables. Every tire manufacturer issues them for each of its tires, and here’s a link to standardized tables  and you can find them online or in manufacturers’ literature. If you’re not sure how to read them, just ask your tire dealer to show you how.


Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

The Load Speed Index is the identification system that replaces the tire Ply Rating and the Star Rating. While there are a few key differences between these rating systems, utilizing the best Load Speed Index will lead to a better purchase when choosing the right tire for your operation.

The load index on tires indicates the load of the tire at the measured inflation pressure.

Quick tip: the specific load index value is equivalent to the rated load for any tire size.

For example, a tire with a load index of 168 equates to a rated load capacity of 12,300 lbs (5,600 Kg). Customers may switch from wide tires to narrow tires depending on the season and application. If you have a tractor that uses wide tires in the spring for planting, you may use a 710/70R42 168 tires on the rear axle, leaving each tire to carry 12,300 lbs at 23 psi.

The speed rating of the tire follows the load index, for ag tires is it usally A8, B, or D. A typical description would read 168 B. These values indicate the maximum speed the tires are recommended for.  The speed rating for each value is:

A8 = 25 mph (40 Km/H)

B = 30 mph (50 Km/H)

D = 40 mph (65 Km/H)

It is always important to make sure to match the maximum speed of the tire to the maximum speed rating of the tractor. In North America, the B speed rated tires will be acceptable for most tractors.  Currently, there are only a few tractors in the market which exceed 30 mph, but for those tractors the D speed rated tires are needed.

With the IF or VF technology in the tire, the load index value increases when comparing the same sized tires. The below tires are speed rated to 30 mph; however, the rated load increases with IF and VF technology (while maintaining a rated inflation of 35 psi):

  • 480/80R50 Standard Radial 159B
  • IF 480/80R50 166B
  • VF 480/80R50 171B

New tire technologies help customers by increasing  load capacity while maintaining the same tire size.

When setting inflation pressures in tires, the axle loads and the operating speeds are critical to ensure proper inflation. Without having a central tire inflation system (CTIS) on your tractor, the inflation pressure needed is based on the fastest travel speed and the maximum axle load. If the tractor is only being used to haul equipment, like a disc or field cultivator, there is not a weight difference between field application and road transport. Once the pressure is set, there is no need to adjust applications. If a tractor is being used with 2pt or 3pt equipment, the rear axle weight changes between field use and road travel. In this example, the inflation pressure of the rear tires would be set based on road axle weight and road travel speed. If the tractor does have a CTIS, the inflation pressure could be set for the field use and then changed for road transport.

Understanding load index and speed rating will allow you to make an educated decision when choosing your next set of ag tires.

If you have more questions, a certified Firestone Ag tire dealer can equip you with the right tires for your operation.


Maxam Tire International
Greg W. Gilland:  Business Development & Ag Segment Manager

Each Agricultural Operation requires equipment designed to maximize the harvest of that chosen crop.

In the case of Tractor applications, the choice of machine size and horsepower selected will dictate the size of tires that will be employed to deliver the planned or expected yield of crop.

Tires are the pressured vessel that create the interface between the machinery and the soil necessary to carry out the farming operation every step of the way from land preparation to crop harvest.

Agricultural tires are designed based on their size geometry, materials, and air chamber to carry a certain amount of weight at a given ground speed and to fit a certain wheel base or equipment.

All Radial Ag tires employ the tire carcass (rubber & nylon casing construction) to carry 20% of the given tire load with the compressed air in tire chamber carrying 80% of the remaining given weight.

The primary function of an Ag Tire is three-fold: u Carry the Load, v Resist Lateral Forces & w Transmit the Torque or Machine Power:

Ag tires are therefore rated by a common index to identify their load capability or carrying capacity at a given speed.

The key objective of any given machine utilizing tires in a farming operation is to choose the optimized air pressure that can carry the maximum weight expected, while providing the least amount of soil compaction.

The yield of the crops produced is directly impacted by the amount of ground pressure caused by the weight of the Ag Machinery due to the topical soil pressure or soil compaction caused by the equipment working in the field.

Growers should therefore choose the tire size and corresponding air pressure that best suits the weight and horsepower of their tractor as optimized to pull their heaviest implement in their operation.

The advent of “Increased Flexion” Technology or IF & VF Technology has revolutionized how the traditional tire is employed through the science of new rubbers and carcass materials able to carry additional weight at higher speeds or reduce soil compaction though decreased air pressure increasing the tire footprint for a given load.

  • IF Technology Tires allows either 20% more tire load at normal pressure or 20% less air pressure for the same tire load
  • VF Technology Tires allows either 40% more tire load at normal pressure or 40% less air pressure for the same tire load

  • The advantage of IF & VF Technology is the capability to reduce soil compaction with lower air pressure by extending the tire footprint or conversely the ability to carry more weight at the same ground pressure or standard air pressure.

To maximize the utilization of IF & VF Technology tires, the Grower should consider adjusting the air pressure of his tires as he modifies the weight being pulled or load being carried by his equipment. The optimal air pressure in every case will reduce the ground pressure thus increasing the yield of crops through reduced soil compaction.

Higher transport or road speeds will demand higher air pressure to sustain the weight and/or corresponding speed to move Ag equipment from the barn to field operation or from field to field. Newer tractor and Ag equipment are utilizing onboard inflation equipment to quickly adjust IF or VF Tires up or down in air pressure to the optimal footprint needed to either move on the road or in the field.

The challenge to the Grower is to employ sustainable methods to adjust and maintain the air pressure of his IF or VF Tires as he moves his equipment from transport mode to field working mode by lowering the air pressure to the absolute minimum needed to float over the soil thus reducing compaction while transmitting the necessary torque or force to pull his equipment and get the job done. The Right Air Pressure for the Right Load is the answer to improved Ag Profits.


Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

Lets first clarify what Load Speed Index means. In modern tire manufacturing each tire has a specific Load Index (LI) and a Speed Symbol (SS) and both together are referred as Load Speed Index. The Load Index (LI) represents the load capacity at the nominal inflation pressure of the tire and there is a direct correlation between load capacity and inflation pressure (the higher the inflation pressure, the higher the load capacity).

These values depend on the tire size (width, ratio and rim diameter) and are all normalized by TRA (Tire and Rim Association) in the US and by ETRTO (TRA counterpart in Europe) meaning that a specific tire size, at a specific inflation pressure will have the same Load Index (LI) for all tire manufacturer (comparable apples to apples).  If for the same tire size, the market offers different Load Index values, it means their nominal inflation pressure (highest inflation pressure allowed) is different. For example, for a Mitas 1250/50R32 SFT 188A8 the nominal pressure is 35 psi (2.4 bar) and for Mitas 1250/50R32 SFT 194A8 the nominal pressure is 47 psi (3.2 bar). Each manufacturer tire catalog will include the table specifying the load capacity for each Load Index (LI).

On the other hand, the Speed Symbol (SS) represent at what speed this Load Index (LI) is referred to. A large combine flotation tire will normally have a A8 Speed Symbol (SS) that represent 25 mph (40 km/h). On a sprayer specific tire, the Speed Symbol (SS) will be a D representing 40 mph (65 km/h).  On conventional tires the reduction of working speed allows higher load capacities of the tire. This can be explained in the fact that at higher loads the tire temperature increases, and the temperature increases also when the speed is increased. So, when we reduce the speed (lower temperature) we compensate for the temperature increase by increasing the load. For example, a Mitas 480/80R50 159A8 inflated at 2.4 bar will be able to carry 9,650 lbs. (4,375 kg) at 25 mph (40 km/h) and 13,500 lbs. (6,125 kg) at 6 mph (10 km/h)

Standard Tires

When looking into a tire manufacturer manual, you will see that for each conventional (non-IF or VF models) tire size there is a specific data matrix with inflation pressure and speed. Each combination (inflation pressure vs. speed) will specify the max load capacity of that tire for this combination. So, when farmer wants to know what inflation pressure he needs for his tires, first he must know the load each tire has to hold and second the speed he will be using for that load. With these two values he can determine the correct inflation pressure for his tire. It is very important to use the correct inflation pressure depending upon the load applied and the speed used as this will allow to have the best performance and the largest footprint (lower compaction) of the tire. An over-inflated tire will result in a higher soil compaction.

IF / VF Technology

When talking about newer and higher tire technology, we must talk about IF (Increased Flexion) and VF (Very High Flexion) type tires. Both technologies represent reinforced tires that allow higher load capacities (20% higher for IF and 40% higher for VF) at the same inflation pressure for the same tire size, compared to conventional tires. Using this same concept, we can say that if we have the same load applied to the tire an IF tire allows to use 20% less inflation pressure and the VF 40% less inflation pressure (always comparing same tire size). For example, comparing the load capacity between the conventional Mitas 710/70R42 173D SFT vs. the VF version Mitas VF 710/70R42 179D HC2000 at 23 psi (1.6 bar), the conventional can carry 12,350 lbs. (5,600 kg) and the VF can carry 17,085 lbs. (7,750 kg). On the other hand, if our tire needs to carry 12,350 lbs. (5,600 kg) the conventional tire would need 23 psi (1.6 bar) and the VF tire would require 14 psi (1.0 bar) for the same load. This reduction in inflation pressure will increase the total footprint and reduce the specific pressure on the soil and the soil compaction.

These higher technologies have the special characteristic that the load capacity will not change by changing the speed only by changing inflation pressure. Making it easier for the farmer to adjust the correct inflation pressure.


Dave Paulk: Manager Field Technical Services

Speed and load ratings on tires have become more important with the influx of tractors and equipment coming into the U.S. from Europe.  When choosing a tire, weight carrying capacity for the weight of the tractor, the intended load, and the transportation speed should all be considered. Some tractors will run up to 45 mph, so the tires must be able to carry the weight required at those speeds.

The load and speed index of a tire follows the size on the sidewall of the tire. Charts are available to show the maximum load capacity of a radial tire at the maximum speed. The charts can be found in most tire manufacturers’ handbooks, as well as on the internet.  An example is a tire may have a 154D/157A8 Load and Speed Index rating (BKT 600/65R38 RT 657). This means that the tire will carry 8,250 lbs. (154 load index) at 40 mph (D speed rating) at 35 psi. This same tire will carry 9,090 lbs. (157 load index) at 25 mph (A8 speed rating) at 35 psi. The higher the speed, the less weight carrying capacity a tire can handle.

Tires that come on Original Equipment tractors are selected by equipment manufacturers to carry the loads of the tractors with ballast to handle the speeds that modern tractors run. Aftermarket add-on’s (ex. saddle tanks) sometimes cause overloading on the tires, usually the fronts, and will cause the tires to fail prematurely. The rears can also be overloaded with the heavier equipment, so correct air pressures are vital to prevent premature failures.

Radial farm tires are designed to run at lower air pressures in the field, at field speeds (5-10 mph). The higher the speed, the less weight carrying capacity a tire has. 8-10 psi may be perfect at field speeds, but when the tractor is transported between fields and/or farms on the highway at 30 mph, the weight carrying capacity is greatly diminished. The tires may need more air pressure to transport equipment on the highway than they do in the fields. Sidewall damage and sidewall separations can occur when tires are run overloaded and under inflated. Realizing that time is precious in the spring and fall during planting and harvest, money can be saved by running the correct air pressures for the application and usage during these times.  Air Inflation Systems are now being offered as aftermarket items, but manufacturers are looking at them as OE options to minimize tire damage and premature failures.

IF and VF technology is being used to enable a tractor to carry more weight without having to widen the tire to the point where it can’t be transported on the highway. This technology can also be used to reduce air pressure to minimize soil compaction in areas where no till and minimum till is used. An IF rated tire will carry 20% more weight at the same air pressure as a standard tire of the same size. A VF rated tire will carry 40% more weight at the same air pressure as a standard tire of the same size. If an IF/VF tire is being used, air pressure can be reduced to carry the same weight as a standard tire. This decreases ground bearing pressure, and thus reduces soil compaction. On the opposite side of the spectrum, sometimes the higher weight carrying capacity is needed. An example is radial implements (IF rated) on planters and cultivators where a bias ply implement tire will not carry the heavy weight of the implements. The VF rated tire is good for sprayers as they run at higher speeds and can handle the weight capacities.

There are still a huge number of bias ply farm tires running in the U.S. market. Bias ply farm tires are designated with ply ratings. The higher the ply rating of a bias farm tire, the more air pressure it holds and the more weight it carries. Bias ply tires, unlike radial farm tires, are not made to run at low air pressures. If bias tires are being used, the load carrying capacity should be checked to make sure they are not being overloaded.

It is important to consider many things when choosing the correct tire for your equipment, your load, and your fields.  BKT technological specialists are available to help with any questions you may have.


Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

Before I get started, I think it would beneficial to review the differences in tire technologies and what they offer.

  • Conventional tires are just that, they have been around since the dawn of the pneumatic tire.
  • IF (Increased Flexion) tires are designed to carry the same load at 20% less inflation pressure than the conventional tire of the same size.
  • VF (Very High Flexion) tires are designed to carry the same load at 40% less inflation pressure than the conventional tire of the same size.

The theory behind IF_VF technology is that as the tire deflects more the footprint becomes larger and the larger footprint means less ground bearing pressure and ultimately less compaction

With so many tire options it can be a bit confusing when making decisions on what one should purchase.  Tractor manufacturers offer a multitude of options.  They actually do a good job of offering the appropriate load and speed index tires on the tractor coming out of the factory.  If a grower is in need of replacement my quick answer is to replace it with a similar rated tire, you really can’t go wrong.

Things get a bit more complicated if that grower is attempting to make a tire technology change which requires a bit more thought.  For instance if they are looking at converting a MFWD from conventional tire technology to IF_VF technology not only will they need to replace all of the tires on the tractor they will need to choose a load index that suits the tractor at its heaviest condition.  Some manufacturers take into account that at slower speeds conventional tires are actually allowed a load bonus or plus up at 20 mph (+7%), 15 mph(+11%) and 10 mph(+34%) as it operates in at different speeds.  See Table 1

Table 1

In this case a 154 load index rated at 8250 lbs. at 23 psi is capable of carrying 11055 lbs. under 10 mph.  When converting to IF or VF there is no load bonus for slower non-cyclical applications.  An IF or VF tire can carry the same load at 40 mph as it does at 10 mph but is not allowed a load bonus or plus ups.  That means that you will need to select a load index that will cover at least as much of the load of the standard tire to meet the load requirements of the tire you are taking off.  See Table 2

In this case the tractor would need to be converted to 165 load index and that tire would need to be inflated to 32 psi in order to carry the same load.  Now granted a tractor typically doesn’t see those extreme loads all the time and inflation pressures can be adjusted much lower for general farming, but it is important that you select a tire with a load index high enough to handle those times when the tractor is experiencing those conditions or you will risk damage and or failure to the tire and possibly damage the tractor.

At the end of the day the grower needs to decide what is best for their operation.  Converting to new technology on an existing tractor is not cheap and they need to weigh the benefits vs the cost.  But if they do decide, it is best they understand the technologies and what gets them the biggest bang for the buck. In addition, doing research and understanding their loads and applications will give them the best chance of being successful with the conversion.  The tire dealer or tire manufacturers would be a great resource to ask questions if they are having trouble understanding.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

Warranty Stop 2019-04-30T15:26:05Z Welcome to AG Tire Talk’s new Warranty Stop Page!

We made it easy for you, posting all the AG Tire Manufacturer’s Warranties in ONE place- with a Radial R-1/R-1W Summary of each.



Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

You could spend hours comparing each and every aspect of every tire company’s warranty policy.  Stubble, Field Hazard, Workmanship and Materials along with the length of the warranty, and how it applies with respect to how the amount of credit is determined based on years of service or wear are all factors to consider.

One of the first things a producer should look for to maximize return on investment with warranty is to make sure they have a local servicing dealer that can handle the claim.  Titan/Goodyear has one of the most extensive dealer networks in North America.  That means in almost every rural area the producer can find someone not only to handle his tire requirements but also administer warranty claims when they come up, making the warranty claim easy and hassle free.  You can confirm a Titan Goodyear dealer is near you by clicking

On Manufacturer Defect Warranty, you should make sure No Charge Free Replacement includes Service and Labor charges, as this can dramatically reduce the cost for a producer if there happens to be an issue.  The initial length of time for “No Charge” replacement due to workmanship issues and on what types of tires is extremely important to know also.

On Stubble Protection Warranty, make sure your Radial Rear is covered before you purchase, as many manufacturers only cover “stubble branded” tires. Some manufacturers require a knock down device be installed after the 1st warranty claim.  That is actually money very well spent any time when you install new tires especially for stubble damage.  Front tires on tractors are changed 3-1 compared to the rear tires.  Common sense tells you it’s because the front tires are knocking down the stubble, so it only makes sense if you put a mechanical device in front, you could actually be tripling the life of the tires.  That is really maximizing your return on invest.

A Warranty Policy is one of many factors a person considers when they are making a tire purchase.  I think the decision to purchase a particular brand is based more on the end users experience with that brand and more importantly how their particular tire dealer services him than it has to do with an actual warranty policy itself.  We all want to do business with people you trust and who treat you fairly.  I don’t think any tire company is intentionally trying to put poor quality product into the field. But if there is an issue, that is where the relationship between the customer and the tire dealer, and then the tire dealer with the manufacturer becomes so important.

Titan is the only company with a team of Ag Specialists in the field whose sole purpose is to assist tire dealers and end users with issues regarding tire application and machine set up to maximize their performance in the field, and also avoid costly downtime due to an unnecessary warranty claim due to misapplication or wrong inflation pressures.  At Titan I like to think we have the end users covered on every aspect of their ownership of a Titan/Goodyear product.




Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

Radial R-1 and R-1W tires are the mainstay of the ag tire market, and they are the work horses of the farm. Investing in a high-quality R-1 or R-1W tire is one of the most productive things you can do to keep your tractor or combine working effectively and efficiently.

But sometimes, things happen. A corn stalk punctures a shoulder, stubble picks away at the tread until air is lost, or some sort of unusual manufacturing defect causes a tire to fail. That’s when a good warranty makes a big difference to your business.

When you shop for a tire, ask your dealer about the warranty that covers it. Of course, the first thing that should jump out is the length of the coverage. Obviously, the company is not expecting many failures during the warranty period, so if they’re willing to back a tire for many years of service, you can figure it’s a very safe bet. When a manufacturer promises long warranty coverage—6 or 8 or even 10 years—it’s making a very strong statement about the quality of its tires.

Look for Stubble Damage, Field Hazard and Manufacturers’ Defect coverage, of course. Consider problems you’ve had over the years, and make sure the warranty would cover them, or that you at least know what’s not covered.

But just as important as the warranty policy is how easy it is to handle a claim. Is there a lot of paperwork, or can the process be handled smoothly? Do you have to haul the tire into town, or can you just send a few pictures from your phone?

Also, be sure to ask your dealer: does this company handle warranty claims quickly and smoothly? Do they have your back? After all, a warranty is just a bunch of legal language until a company makes good on it.

That’s why we’re so proud of our ATG Warranty Wizard app. It’s a smartphone app for iPhones or Androids that makes a warranty claim really simple to file—it walks you through a few questions, you take a few photos with your smartphone and push “send.” The information goes directly to the people who need it to process your claim, and they handle each claim promptly. It’s as simple as that.

As for Alliance Tire’s warranty terms, our new farm tire warranty is one of the best in the industry. Here are some highlights:

  • Steel-belted Ag Radials: 10 years of wear coverage
  • Non-steel-belted Ag Radials: 7 years of wear coverage
  • And we still have our great, 3-year stubble damage and field hazard policy for qualifying Ag tires

Tires worn less than 25% and deemed in “adjustable condition” will be replaced without charge (excluding mounting and service charges). Tires with more than 25% wear deemed to be in adjustable condition will be prorated based on the remaining tread depth. Details and the full ATG warranty policy are available online at

Here’s the bottom line: a warranty is an important tool and a major consideration when buying a tire—and so is the company that’s backing it.




Dave Paulk: Manager Field Technical Services

Agricultural tire warranties should be an important consideration when buying tires. Most all manufacturers have a Limited Manufacturer’s Material and Workmanship Warranty. The time and conditions of the warranties vary from manufacturer to manufacturer.

No matter how well a tire is made, there is always a risk that a tire may become unserviceable due to the conditions it is used in. A warranty provides protection should a customer have issues with a tire due to a manufacturer defect or material related failure. There are steps to prevent the possibility of tire failure.  Running the correct air pressures and loads diminish the chances of having to adjust a tire under these circumstances and conditions.

Some companies offer a Field Hazard and Stubble Damage Warranty, comparable to the Road Hazard Warranty on automobile and light truck tires. The Field Hazard part of this warranty covers tires that become unserviceable due to non-manufacturer related circumstances. This can be the most important part of the warranty to help a farmer protect their investment with circumstances that they sometimes can’t control.

Stubble Damage, the second part of this warranty, is caused by corn, cotton, soybean, etc. stubble penetrating the tire and causing air loss. With most manufacturer’s warranties, the tires must be unserviceable and not able to be repaired to be adjusted under this provision.  To minimize stubble damage, mount equipment to the front of the tractor to push the stubble over to eliminate stubble penetration into the tire. Also, if possible, cut the stalks taller so the front tires push stubble over instead of directly running over it helps.  Tires are made of rubber and fabric and unfortunately aren’t indestructible. This is an important part of the warranty of help a farmer protect their investment of tires.

BKT has a both a Limited Material and Workmanship Warranty and a Field Hazard and Stubble Damage Warranty to help farmers protect their investment by purchasing BKT agricultural tires.

BKT’s Limited Material and Workmanship warranty covers Radial agricultural tires for 9 (nine) years from the date of purchase or the date of manufacture if proof of purchase cannot be furnished. This will cover any condition considered to be a manufacturing defect by BKT.

BKT’s Limited Material and Workmanship warranty covers Bias agricultural tires for 3 (three) years from the date of purchase or the date of manufacture if proof of purchase cannot be furnished. This will cover any condition considered to be a manufacturing defect by BKT.

BKT has a 3 (three) year Radial Field Hazard and Stubble Damage Warranty from the date of purchase or date of manufacture if proof of purchase cannot be furnished. This covers both for a period of 3 (three) years. The tire must be unrepairable to be considered for warranty under this provision.

BKT has a 1 (one) year Bias Field Hazard and Stubble Damage Warranty. This is determined from the date of purchase or date of manufacture if proof of purchase cannot be furnished. The tire must be unrepairable to be considered for warranty under this provision.

There are tables in BKT’s warranty to determine warranty amounts for both the Material and Workmanship Warranty and the Field Hazard and Stubble Damage Warranty.  They are based on time in service and tread wear.




Continental Agriculture North America
Dana Berger, OE Sales Representative and Farm Project Lead

Continental released their 10-year Agriculture Tire Warranty for the United States and Canada in February 2019. When discussing what we could offer farmers, one of the first suggestions was to re-enter the market with an industry leading warranty length. Why not extend our confidence in our new products by offering a 10-year warranty? We wanted to focus more on what the farmer needs from a tire supplier – so we did.

With today’s crops increasing their strength against the elements and maximizing their yield for our ever-growing populations, tire manufacturers are faced with constant challenges. Continental is facing those challenges with new technologies, like our N.flex carcass and single wire bead along with one of the best warranty programs on the market.

Some farmers will hold on to a tractor for the entire length of its life. For those farmers, the extended support from a tire supplier proves that we value their hard work. On the other hand, farmers who lease their equipment will benefit greatly from our Stubble Damage and Field Hazard coverage. This comes back to the density of the stalks causing tire damage. With the proper stalk dampening procedures in place, a farmer can be confident that Continental will stand behind them, should there be damage from regular operation. This includes any concerns from piercing or blowout situations related to field hazards.

Tires are an investment for a farmer. Even leased equipment must often be returned with a tire in good condition within reasonable treadwear use. For a R-1 and R-1W tire, the farmer needs to consider the tread depth and overall wear when they turn in their equipment. Our warranty can help the farmer not have to purchase a full priced tire that they won’t benefit from, upon return. If they need to replace a tire from workmanship and materials, field hazard or stubble damage, we will prorate the remaining tread depth percentage with a credit toward a new Continental R-1W tire.

Ultimately, a warranty is all about the customer. Continental’s Radial Agriculture Tires are “Engineered for Efficiency” on the farm. We look forward to joining some of the country’s hardest working professionals in the field.

Basic Coverage Summary:

Any tire that becomes unserviceable from a covered warranty condition will be repaired or a pro-rata credit will be issued towards replacement with a new Continental or General Tire brand tire. This credit will be determined by applying the lesser of the percentage of actual remaining tread depth (RTD%) of the covered tire, or the maximum credit based on the age (from purchase date) of the covered tire as indicated in the attached chart.

Stubble Damage Coverage:

If, in normal agricultural service, a covered tire becomes unusable or not repairable due to Stubble Damage (piercing or erosion due to plants and/or crops), a pro-rata credit will be issued towards replacement with a new Continental a pro rata basis based on the purchaser’s then current (at the time of adjustment) purchase price for the covered tire. The first year has 75% pro-rata credit, the second year has 50% pro-rata credit, and the third year has 25% pro-rata credit.

In order to qualify for Stubble Damage Coverage, the owner-user must use reasonable efforts to reduce Stubble Damage such as adjusting tire spacing to run amid the crop rows, knocking down stubble with the help of mechanical devices readily available through equipment manufacturers, and running parallel to the rows for the first tillage pass.

Field Hazard Coverage:

If, in normal agricultural service, a covered tire becomes unusable or not repairable due to Field Hazard Damage (piercing or blowouts due to hazards commonly encountered in agriculture field settings),a pro-rata credit will be issued towards replacement with a new Continental a pro rata basis based on the purchaser’s then current (at the time of adjustment) purchase price for the covered tire. The first year has 50% pro-rata credit and the second year has 25% pro-rata credit.

CONTINENTAL FULL WARRANTY: Continental General Warranty



Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

When purchasing new equipment or new tires for your current equipment, does the tire manufacturer’s warranty or policies factor into your decision? Does your tire dealer or equipment dealership help you understand the warranty that comes with your purchase? What is the difference between a warranty and policy, and what should you ask your dealers when comparing the warranties or policies?

The Firestone Ag manufacturer’s warranty is a program in place to help customers when the tire becomes unusable for any reason within the manufacturer’s control. The manufacturer’s warranty applies when the customer uses the tire correctly, but it becomes unusable. In Firestone’s published manufacturer’s warranty, there are examples of what typically is not covered under the manufacturer’s warranty, like tire damage due to apparent overloading, abuse of the tire, rapid tire wear, mounting damage or improper repairs. The list of typical conditions not covered is in the Firestone manufacturer’s warranty, which can be found at

Firestone agricultural radial tires (excludes Performer EVO–branded radials) have a manufacturer’s warranty of nine years and six years for the Performer EVO–branded radial and bias tires. The Firestone manufacturer’s warranty start date is based on the tire or new equipment’s original proof of purchase (POP) date. If the POP is lost, Firestone will use the DOT serial date code of the tire to determine the age of the tire. This serial date code is found on the sidewall of the tire, and shows the week and year the tire was produced. The published manufacturer’s warranty outlines the amount the customer pays, based on the age of the tire. The Firestone warranty is transferable between owners of the equipment, which means it doesn’t matter if you’re the first, second or third owner — the Firestone manufacturer’s warranty stays with the tire.

Firestone Ag also provides a Stubble Damage Policy and/or a Field Hazard Policy on R-1 and R-1W tires. A policy is extra protection that extends to the customer when the customer follows all the recommended operating instructions, but damages a tire early in its life. The  Field Hazard and Stubble policies are there to help customers when  a tire is damaged beyond repair and the damage is not within the tire manufacture’s control. Firestone’s Stubble Damage policy is a three-year program, and the Firestone Field Hazard policy is a two-year program. Unlike the manufacturer’s warranty, the policies only apply to the original owner of the tire. Just like the warranty, Firestone will use the proof of purchase as the start date of the policy. The published Firestone policies can be found at, with a full explanation of what is covered and the common limitations of the policy.

The questions to ask your dealer when comparing the manufacturer’s warranty or policy:

  • Do these tires have a manufacturer’s warranty or policy?
  • Where can I find the published manufacturer’s warranty or policy?
  • How many years are the tires covered under the manufacturer’s warranty?
  • How much do I need to pay if there is a warranty or policy claim?
  • Is the labor or service call covered by the manufacturer?
  • Does the warranty or policy transfer to the next owner?

Asking these questions is a great way to understand the total purchase price of the tires. A certified Firestone agricultural tire dealer will be able to walk you through the warranty that comes with every Firestone agricultural tire. If you have additional questions or want to do some initial research, you can read and print Firestone’s warranty and policies at Firestone Warranty




Warranty is a word that should symbolize manufacturing quality and the compromise of the tire manufacturer to stand behind his product with high quality and after sales support. This compromise must be complemented with the local tire dealer knowledge and support. This combination assures that the final tire customer has peace of mind.

There are several aspects to consider when analyzing tire manufacturer warranties and how its applied in each case. Several steps must be followed in order to have a hassle-free process in case a warranty has to be used. Always the process starts with your local tire dealer and he will determine if the issue is warrantable and will follow up the process with the tire manufacturer. If your local tire dealers do not respond to your expectations, most tire manufacturers offer a toll-free number to contact them. Please don’t abuse this resource and use it only as the last resource.

First point to consider is the length of the covered period, when it starts, how the credit is applied in case the warranty is accepted, paperwork required and what additional perks the tire manufacturer offers. For most cases, especially with well-known brands warranty coverage period starts when the tire is sold to his final user. For example, a farmer that bought a tractor, the start of his warranty is the date of the tractor invoice – it’s important to keep a record and proof of purchase for a claim. If this information is not available, the start of the warranty is the date of manufacturing of the tire (date code) stamped on the tire – normally 4 digits representing the week and year of manufacturing.

Claim type. The tire manufacturer warranty covers – during the covered period – for defects in material and/or manufacturing. The tire must be used as its designed to be used, the warranty will not cover for improper use, maintenance, storage and/or abuse of the tire. Cosmetic blemishes – as small stubble damage – that will not affect the tire performance are not warrantable cases. Always consult with your local tire dealer if your situation is covered by the tire manufacturer warranty before starting a claim. In the case the tire dealer agrees on the viability of the claim, he is the responsible to collect all the information and evidence of the claim and submit it to the tire manufacturer for analysis. Even in this case, always wait for final manufacturer approval of the claim.

Type and quantity of the adjustment from the tire manufacturer. This criterion defers between manufacturers and most apply a percentage of reduction per year. For example, in a 5-year warranty, the adjusted credit will be reduced by 20% for each year of usage (a 3-year-old tire would get a 40% credit). For Mitas tires, the credit is based on remaining tread depth at the time of the claim (takes in account the tire usage). So, if a tire is 6 years old and the tread dept is 50% of the original, the credit would be of 50%. Once the claim has been accepted by the tire manufacturer, the credit will be issued to the local tire dealer that initiated the claim and forwarded to the end customer. In most cases the credit is applied toward the purchase of the replacement tire.

Some tire manufacturers add additional perks to their warranty. Mitas added to the warranty what is called a Field Hazard for the first 3 years of covered warranty, independent from any manufacturing or material defect. This perk applies when a tire suffers a damage beyond repair (puncture by deer antler for example), where the tire functionality is compromised, and the tire has not been misused. In this case Mitas will help the final tire owner with part of the replacement tire cost proportional to the length in service.

Another policy to consider when purchasing an agricultural tires is related to Stubble Damage. Some manufacturers include this policy in their warranty, be sure to ask for the Stubble Damage policy and review it with your tire dealer.

It is important to operate tire within the load and speed limits at the air pressures specified by manufacturer according to individual tires size, type, and load capacity and to maintain proper alignment of wheels, avoid overloading and any other misusage of the tires. (Read the owner-users obligations in the warranty manual).

As a final consideration always remember to follow owner’s obligations, perform preventive maintenance and rely on a professional tire dealer. Tire manufacturer support and response is key to the success of an operation. A long warranty period is no good if the dealer is not supportive or there are two many clauses excluding the warranty. Always review all the requirements of the warranty.





CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

Growers who are looking to purchase radial Ag tires should start the process by identifying the product or products that best fit their needs. After a grower identifies one or more candidates, they should gather information on costs, availability, past experience and inventory. It may be prudent to check these items with several dealers. The warranty policy should also be a big part of your fact-finding process. The warranty coverage may be a determining factor in your purchase.

CEAT’s FARMAX brand Ag radial tires are covered by a limited Ag radial warranty that provides seven years of Workmanship / Materials coverage. If the tire becomes unserviceable, unrepairable or unsafe during the first seven years in service due to a Workmanship / Materials defect, the original owner is covered by this seven-year warranty. During the first two years, there is a No Cost Replacement as long as the tread depths are at 75% of the original tread depth or more. Credits for years three through seven are pro-rated on a tread removal basis.

CEAT also offers a Field Hazard / Stubble Damage warranty for a three-year period on all CEAT Ag tires. If the tire fails or is unrepairable during the first three years in service the grower has coverage at a 75% level for the first year, 50% during the second year and 25% coverage during the third year.

Time in service for warranty calculations is based on dealer invoice to grower. If the invoice is not available, the fallback position is the date code molded on the sidewall. CEAT is not responsible for any associated costs or damages caused due to the failure or the replacement process.

Please see the complete warranty policy for all details of CEAT’s FARMAX Ag radial warranty.




Maxam Tire International

Greg W. Gilland:  Business Development & Ag Segment Manager

A Grower should first and foremost find Ag tires that meet his definition of “Value” for his Farm, Ranch or Operation. Our Maxam Agrixtra Family of Radial R-1W Ag tires are designed to deliver the best possible “Value” to a Grower through superior traction, ride comfort, and endurance at a competitive price. Our New Ag Warranty was developed to ensure we give that same grower “peace of mind” in his purchase of Maxam Radial Ag Tires by protecting his investment.

The protection we provide for our Radial Product Line Workmanship & Materials is Eight (8) Years, with a Two (2) year Free Replacement <25% of wear that includes standardized labor and service reimbursement.  After free replacement time frame, our Workmanship & Materials warranty is based on years of service only, not tread depth.

Maxam also offers both Field Hazard & Stubble Damage protection with Four (4) years of coverage, based on both years of service and tread depth.

Lastly, we offer Four (4) year Workmanship & Materials warranty for scraper service, in addition to the above Agricultural service coverage noted.

See the details of our coverage by clicking the link for 2019 Maxam Ag Warranty Brochure, or as noted in the below Summary Table:




Michelin Ag
David Graden: Operational Market Manager – Agriculture

No one really wants to spend their valuable time sending in warranty claims for their tires. The fact is, in the case of Ag tires, most warranties tend to cost you. Typically, when a warranty claim is filed, you end up paying for the rubber/time used on that tire; not to mention the down time, mounting, labor etc. A typical comment I hear is, “That’s why I paid so much for this tire to begin with!”

Good point, however, regardless of whom the tire manufacturer is, there will be occasional manufacturing issues that cannot necessarily be controlled. For instance, folds in the rubber being extruded into the mold, shipping damage, delamination of one rubber compound to another, etc.

When choosing new Radial R-1/R-1W tires for your machine, it’s important to consider the warranty that comes with that tire. This warranty should not only protect you from Manufacturer Defects, but some will even protect you from possible damages caused by normal use.

For example, Michelin Agriculture tires come with a standard 9yr Workmanship and Materials warranty, where the first 2 years are No Charge to the customer including Service and Labor for replacement. After that, we start at 30%, 40%, and so on down to 9yrs.  It’s also important to know that Michelin credit is based on years of service only- not treadwear & years of service.

We also carry a 3yr Stubble Hazard warranty on all of our tires, with select “stubble shield” tires (YieldBib & MegaXBib2) having a 4yr warranty, again with Michelin credit based on years of service only- not treadwear & years of service.

To round out the total Michelin Agriculture Warranty offer, we also carry a scraper warranty, and if you wanted to try a set of Michelin Agriculture tires, we have a standard 90 day total satisfaction guarantee, where you can try the tires for a season and return them if they don’t work for you.

Bottom line, the environment in which agriculture tires work is severe. When you make your next purchase decision, it is very important to start with a quality product that will minimize downtime and additional cost down the road.  Lastly, it’s important to consider the entire warranty program. Not just one aspect.


Preventative Tire Maintenance to Reduce Downtime 2019-03-02T18:46:00Z  

Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

Tires are so durable in the field that it’s easy to forget that they can be damaged if they are stored incorrectly. The big hazards are letting them get out of shape and exposing the rubber compound to degradation.

The best way to store tires is standing up. If you stack them, be sure not to put smaller-diameter tires on the top of the pile—they can damage the sidewalls of the tires below them. A good rule is to avoid putting a tire on a stack that doesn’t cover most of the sidewall area of the tire below it.

If your tires are mounted when you store them, over-inflate them by 5 or 6 psi for storage to help them retain their shape over the off-season.

Rubber compounds are susceptible to damage from hydrocarbons, so keep them away from gas, diesel, oil, paint, solvents and mechanical fluids like hydraulic or brake fluid. They can also be weathered by exposure to UV, so keep stored tires out of direct sunlight.

Ozone can also degrade compound, so don’t store tires near electric motors, welders or transformers, which all create ozone as they operate.

As you get ready for the growing season, inspect your tires carefully. Make sure you don’t have any nails or other objects wedged into the tire (you’d be surprised what can have escaped your notice). Check sidewalls for blisters that indicate separation or impact damage, and for slashes or cuts that could threaten the integrity of the casing. Look over your tread for wear, chunking or cracks.

And, of course, adjust your inflation pressure to the proper level for the load and speed you will be operating at.

Invest in a tread depth gauge. They’re not expensive, and they’re easy to use. All you have to do is rest the feet of the gauge on your tread lugs or blocks and extend the probe into the space between the lugs. The key is to do it several times at different places in each tire. That way, you’ll pick up indications of uneven wear, which are important for determining whether your inflation pressure has been correct, and whether you need to rotate your tires more frequently.

Examining tread depth is important in determining whether your tires are worn out.

There’s no real, set number for when a farm tire is worn out. Obviously, if you see cords or damage, it’s time for a new tire. But there’s a little wiggle room on tire replacement based on what you expect that tire to do. If you’re counting on great traction to pull a disk or a planter, you’ll need some rubber on those lugs to get a good grip—same thing if you tend to run in muddy or slick conditions.

However, if the weather is dry or we’re just talking about a chore tractor that you use to pull a feed mixer or haul things around the yard, you might be able to squeeze an extra season out of a set of tires that are down to 20/32″ or so.

Think of it this way: if you just bought a thousand-dollar hunting rifle or a new drone, you’d make sure you took good care of it and stored it out of the weather. Your tires are worth that much or more. Treat them accordingly and you’ll be protecting your investment and setting yourself up for good performance this spring.

Continental Agriculture North America
Albert Sumera, Continental Commercial Specialty Tire Technical Solutions

As with any other tire that will not be used for a period of time, agriculture tires must be kept in clean, dry conditions and ventilated premises away from direct sunlight. They must be kept away from any source of ozone (for example an electric motor or transformer); away from chemicals, solvents, and hydrocarbons that may affect the nature of the rubber; and away from any objects that may pierce the rubber (sharp or pointed metal objects or tools). They should also be stored away from flames or hot objects.

Tires should be stacked if mounted, to avoid damage due to tension or compression. If mounted on a vehicle, de-ballast them as much as possible and over-inflate by 0.5 bar (7 psi) versus the operating air pressure used. Before the start of operations next season, check the physical condition of the tires and adjust to the correct operating air pressure.

Agriculture tires are normally used for a long period of time, however in instances when there is an observed substantial slippage (approximately more than 15%) depending on the surface of operation, the tires may be considered “worn out”. Being worn out is relative to where the machine and tires are being used and there is no general principle that can be applied to every situation.

Agriculture Tire Tread Depth Measurement:

  • Tread measurement should be made on properly mounted tires. Tires normally grow after first inflation. This effect is very significant the first few hours and can go on for the rest of tire life in minimal dimensions.
  • Recommendation for precise measurements at “new” condition:
    1. Set air pressure to 2.0-2.5 bar (29-36 psi) at mounting
    2. Run the tires for a few miles on road at max tractor speed
    3. Adjust the air pressure to the operating air pressure
    4. Measure the tread depth the next day (24 hours later)
  • Because of difficulty and variance in measurement of tread depth of agriculture tires, it is decided to use the center-line as the simplest measurement method.

1. Measure on four locations along the center-line of the tire (see image 2).

2. Use a flexible steel ruler to align with the round shape of the tire diameter by pressing the top of the ruler to the inside of lug 1 and the bottom of the ruler to the inside of lug 3 (see image 3). If a flexible steel ruler is not available, you can also use a hack saw blade.

3. Measure with a tire gauge down to the deepest point between lug 1 and 2 (see image 3).

4. We recommend measuring the tires every 500-1,000 hours, but the first measurement after fitment should be done earlier. During the first 100 hours the wear rate is generally higher (which is normal for all types of tires).

Dave Paulk: Manager Field Technical Services

As spring tilling, spraying, and planting begins, farmers are reliant on good tires with minimal downtime. At this point of the year, downtime costs time and money- but before equipment is stored for the winter, there are things that can be done to minimize tire and equipment problems in the spring.

1. Tires should be checked for cracks, cuts, bulges, or any other type of visible damage. If there is any damage or possibility for failure, this gives time to replace or repair tires before they are needed again. Be sure to check tread depth. If the tire has less than 20-25% tread left, the tires may need to be replaced sometime during the next year. This gives the farmer time to budget for new tires.

There are several ways to measure tread depth. An OTR tread depth gauge can be used and bought through suppliers that cater to the tire business. Also, a straight edge with a ruler can also be used by laying the straight edge over the top of the lugs. Measure from the base of the tire to the straight edge with the ruler as close to the center of the tire as possible.

2. Make sure lug nuts are tightened to correct specifications. Check the bolts for wheel weights to ensure they are tight.

3. Inflate tires to the maximum recommended inflation pressure by the manufacturer for storage. Ambient air temperatures can cause air pressures to move up and down during the winter months when the equipment is not in use. Air pressures generally decrease in cold weather, causing the tires to go flat if they are not inflated enough. If tires go flat during the winter, the rim can damage the sidewalls by sitting on them. It is a good idea to check tires periodically while the equipment is stored to ensure they don’t go flat.

When taking the equipment out for use after storage, set air at correct recommended pressures to carry the weight of the tractor and equipment. This will ensure the tire is not damaged and will minimize soil compaction. Do not drive on flat tires.

4. Make sure tires are clean before storage. Clean the mud, sticks, and rocks from lugs and remove mud from the rim and weights (if wheel weights are used). In general, it is a good idea to store the equipment clean. When it is used again, it is ready to go.

5. If possible, it is best to store equipment inside in a cool and dry place. This keeps the sun, wind, rain, and snow from weathering the tractor and the tires. Ozone in the air and sunlight can cause rubber to age prematurely. It is best to keep rubber products away from electric motors, oils, fuels, and resins. If the tractor will be sitting for several months or more, it is best if the tires are not parked on rocks or asphalt. Rocks can damage tires if they lose air pressure. Also, asphalt is an oil-based material that will cause rubber to deteriorate over time. If the tractor must be left outside, cover the tires with a waterproof tarpaulin to avoid contact with ultra violet rays and bad weather.

There is really no cut and dried way to determine when it is time to replace tires based on tread depth. A tire that needs to be replaced in wet dirt may be fine in dry dirt. As tire lugs wear down, they can start slipping excessively which can increase fuel costs and time. Newer model tractors have wheel slip indicators where they should be in the 8-15% range, the closer to 8% the better. If the tire seems to be pushing dirt back behind it farther than normal, there is a good chance there is too much slippage. At this point, tires should be changed for optimal performance, and fuel and time savings.

All of these tips will help maximize tire life and minimize downtime.

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

Ag tires are designed to withstand the usage conditions of their respective application, but in order to achieve their full performance potential they must be maintained appropriately, which includes the condition in which they are stored in the off season in order to minimize the chance of experiencing an ozone/weather cracking condition over the winter months when the equipment is inactive.

Rubber compounds that are exposed to the atmosphere are formulated to resist deterioration caused by ozone. It may be hard to believe but the rubber compound properties constantly evolve due to their service and storage conditions. Improper storage can result in various tire conditions to develop including weather/ozone cracking also known as veneer cracking, dry rot, and weather checking if tires are not stored properly when not in use.

Ozone/weather cracking appears as a condition where small cracks/checks develop sometimes very quickly. This condition can appear from normal aging or late in its service life. It typically appears in higher stress areas on the tire near lettering of between the lugs.

Normally it does not affect the service life of the tire however, it can be aggravated by improper storage and/or exposure to high concentrations of ozone.

In order to help avoid potential tire degradation, maximize tire performance, and ultimately prevent premature removals, we generally recommend a few things to help minimize these types of conditions.  If you think about what causes the condition, the surface of the tire or rubber with tension or stress and exposed to sources of ozone and UV light the common sense approach would be to eliminate those.

In a perfect world the best case scenario would be to block equipment off the ground to remove the load and let air out of the tires to relieve the stress on the tire surface.  In addition, the unit should be stored in a covered environment away from sources of ozone which would include electric motors/machines, engine exhaust, welding equipment, battery chargers, transformers, and mercury vapor lamps. Other equipment that may produce sparks or electrical discharges should also be avoided. Covering the tires with an opaque wrap will eliminate the chances any UV light to attack the surface of the tires.  I realize that it seems like a lot of work, but if you follow any of these suggestions or you realize you are accidentally exposing you tires to harmful elements you can take whatever counter measures to minimize the risks.

Depending on who you talk to and the applications, tires can run for decades and be literally smooth and they still perform the job just as well as the day they installed them.  Of course those are rare but my point is that depending your performance expectation the idea of “worn out” may differ.  Most companies will consider a tire “worn out” when the tread depth is less than 80% or 90% of the original tread depths.  Warranties are based on this.  If you are experiencing excessive reduction in performance due to lack of traction then it may be time to start shopping for a new set of tires.

Typically tread depths on Ag tires are taken across the center of the tire between the nose of the lugs. Using a depth gauge is the best way but you can use a ruler or tape measure with a straight edge to get the same measurement.

Precision Inflation, LLC
Ken Brodbeck, VP of Technology

Time to change horses?

Some things never change.  Grandpa or Dad checked the team of horses every day.  Adding new shoes, repairing a harness or replacing a feed box.

Grandpa spent 5 to 10 minutes every day caring for his horses.  What if we spend 5 minutes per week checking our tires rather than brushing and feeding the horses?

At the end and beginning of the season:

  1. Check TIRE PRESSURE!! Inflate to recommended plus 2 to 3 psi for weather changes.  A tire monitoring or On the Go Inflation System makes this simple!
  2. Check for any cuts or breaks in the tire tread, shoulder, sidewall and bead area.
  3. Is there irregular tread wear? This may stem from over or under-inflation!
  4. Store tires in a dark and electric motor/welder free area. Sun and ozone kill tires.
  5. Keep petroleum-based liquids and grease away from tires.
  6. Reset tire pressure at the beginning of the season for the machine’s heaviest load, such as a large front fold planter.
  7. At a minimum, check tire pressure once per week during use.

When to put the tire/horse out to pasture?

  1. When the R-1 or R-1W tire will no longer do the job!
    1. Excessive slippage in heavy drawbar applications
    2. Will no longer hold air and cannot be repaired
    3. There are numerous cuts or cracks into the tire cord body
    4. Your favorite tire dealer has a special rebate deal. A half worn tire may value to trade in for a new set of shoes!
    5. If you need to measure tread depth, choose the worst wear location, lay a straight edge across two tread bars and measure to the base of the tire with a ruler.

Our grandfathers took 5 minutes every day to feed and water the work horses, we should take 5 minutes a week to check our iron horses’ rubber shoes!

Michelin Ag
David Graden: Operational Market Manager – Agriculture

Over the years, I have seen many methods producers have used to either prolong the life of their tires or prevent the effects of winter storage on the following season. These would include parking their machine (tires) on wood or concrete blocks, taking weight off of the tires by raising the machine off the ground, covering tires with a sheet or tarp, increasing the air pressure to maximum psi, etc. The reality is, there are only a couple of simple actions a machine owner should take to help maximize the life of their tires and ensure optimum performance the following season.

After harvest season has come to an end, your machinery has been washed and you are ready to button up things for winter, I recommend parking your machine in a cool dry place. Washing your machine thoroughly will show evidence of any fluid leaking throughout the storage period. Additionally, make sure your tires aren’t sitting in chemicals, hydraulic fluid, fuel or oil. Petroleum based fluids will eat rubber and cause your tires to crack at the contact area.

Next, raise the air pressure of your tires to the maximum air pressure recommended on the sidewall of the tire. As the ambient temperature falls, so does the psi in your tires in addition to the natural loss of air pressure over time. When you return to use your machine, and pull out of storage for the season, reset your air pressures to the recommended psi. Your tire manufacturer representative should be able to assist you with this. As I have stated before, all Michelin Ag reps have the capability of weighing machines and recommending exact air pressures to help your machine perform exceptionally well.

Determining when a Michelin Ag tire is worn out is a great discussion with any end user. If you were to ask a producer to tell you when their tractor tires are worn out, they would probably give you a confused look and a response of, “When the tread is gone!”

Michelin Ag tires are standard R-1W with very specific rubber compounds and lugs designed to wear slower and more consistent than R-1 competition, as shown below. By design, when a Michelin Ag tire is deemed by many to be worn out, there is still plenty of tread with sharp biting edges with a consistent void ratio.

Rubber has a shelf life much like the bread in your pantry. Now that aromatic oils are no longer used in tire rubber, it begins to dry out as that tire ages.

For example, let’s say a typical tractor tire will last about 12 years, although the sidewalls are beginning to show significant age and reaching the end of their life- in many applications our tire will continue to complete the job efficiently with minimal slip due to design.  Further, many folks would add a tube and use as much of the remaining tread as possible.

If you wanted to keep an eye on your tread and track my thoughts here, Michelin recommends taking tread measurements at the center of the tire, at the lug nose. If your tire pressures are set to recommended psi for the weight carried, your tires should wear nice and evenly across the face of each lug. If your tires are not wearing this way, you could have a mis-mounted tire or have a mechanical issue causing that tire to wear unevenly. Consult your manufacturer’s rep for recommendations or diagnostic.

Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

After a hard season and harvest complete, it is now time to take a well-deserved break until the next growing season. This time of the year allows us to perform maintenance operations neglected during the growing season due to lack of time and prepare the equipment for a hassle-free performance next season.

It is important during this time to check your tires, as they are a key component of your operation. There are several points to consider when checking tires during the off season:

1 – Check for external damage that could compromise the tire’s structural integrity or performance. For example; nails, deer antlers, deep cuts, missing parts, etc. If any external damage is found, consult with your tire expert if you think it will affect the performance of the tire
2 – Check for correct bead seating on the rim and potential tire to rim slippage. If any issues are observed here let your tire expert assess the situation and correct if necessary.
3 – Check the bead area for material between the bead and the rim. If anything is found, be sure to remove it. If it’s difficult to remove let your tire dealer do it for you.
4 – Check the tire for signs of any uneven or excessive wear pattern that can be related to incorrect tire inflation pressure, incorrect tire size selection (that differ from a correct lead value depending on the tractor inter-axle ratio), excessive tire to soil slippage or damage/wear on steering components.
5 – Check the height of the lugs and replace the tires if the lugs are below 20-30% of its original height. The original measurement can be found in the tire manufacture data-book and web page. The lug height, or tread depth, is defined as 32nd of an inch and must be no less than 20-30% of the original value. If it’s below this value, the recommendation is to replace the worn-out tire. Low lugs significantly reduce the capability of the tire to transmit the equipment’s power to the ground, increasing the tire to soil slippage. The height of the lug can be checked by placing a flat plate between two adjacent lugs and measuring the depth of the inter lug area. This measurement must be taken at 1/3 and 2/3 of the length of the lug. Check in several areas of the tire.
6 – It is always recommended to store the equipment inside a shed and away from direct sunlight. Direct and prolonged exposure to sunlight can create superficial cracking and potentially dry out the tire.
7 – If possible, lift the equipment and place it on stands to allow the weight of the load to be released from the tires. You can also increase the inflation pressure so the tire maintains its round shape as much as possible. Take in to consideration that no tire is 100% air tight, so the tires will lose some air over time. Once the new season starts, recheck and adjust the inflation pressure to the recommended values depending on the equipment and application.
8 – If the tires are removed from the equipment to be stored during the off season, for example a floater set for sprayers, be sure to store them standing upright.
9 – Clean the tires as much as possible to remove dirt and other debris.
10 – Don’t allow the tires to come in contact with petroleum-based products or solvents.
11 – It’s recommended, when replacing worn out tires, to choose the same brand and size already installed for each axle of the equipment. This is because they are approved by the OEM’s. Tire specifications vary slightly between brands, even for the same nominal size, and it can damage your transmission if not chosen correctly. Also never mix radial with bias tires or R-1 with R-1W.
12 – In case you decide to change the size of the tires, consult with your equipment dealer to ensure the change is acceptable. Having a “non-approved” tire combination can damage your gearbox and final drives.

Always remember that the tires are a fundamental part of the equipment and taking good care of them will assure the correct, expected performance.

Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

Before planting begins, farmers should perform a standard equipment check to make sure tractors, tillage and planters are in good working order. Checking oil, hoses and fittings is typically at the top of mind – but we can’t forget about tires. Firestone Ag has created a seven-step Tire Check list to help farmers quickly but effectively check their tires this off-season so they can maximize up-time when planting and growing seasons arrive.

The Firestone Ag Tire Check list provides seven steps that help to identify signs of tire wear. Regularly checking tires can help prevent and avoid more time-consuming problems in the field, therefore increasing the tires’ lifespan and a farmer’s profitability. After completing the 7-step list, if any abnormalities are found, a certified Firestone dealer can inspect the tire to know if repairing or replacing the tire is the best option for the farmer.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

R-1 or R-1W: TIRE MANUFACTURER’S ANSWER 2018-12-29T03:40:00Z  


Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

In the ag industry traction tires are classified by the depth of tread using the nomenclature R-1, R-1W. This industry standard allows tire manufactures to work within the standardized classifications so machine manufacturers and end users can properly compare tires. The R-1 has been the standard general farming tire for decades. Tread depths for R-1 tires depending on the size will run from 1.25” to 1.75” deep depending on the size of the tire. R-1W is of European origin, some call it the European R-1. R-1W tires are generally 20%-25% deeper than a standard R-1

That being said the question then arises what are the benefits of both and what applications are best for each. Typically on smaller HP tractors (<150HP) the manufacturers will fit the tractors with the R-1. These tractors are used in lighter more general applications. In addition R-1 tires tend to be less expensive and more cost effective for the manufacturers. However, R-1 tires do tend to perform better in some applications. In applications where the tires will see dryer harder conditions the R-1 will outperform and outlast the R-1W in most cases. R-1W’s perform better in softer slightly wetter soil conditions and typically clean better in those wetter conditions.

For example, a self-propelled sprayer is a good candidate for R-1 tires. The 25% deeper lug of the R-1W tends to leave deeper lug or cleat marks in the field and when making turns on the end rows they tend to rut and disrupt the residue more. During long transport runs the deeper lugs tend to heat up and flex more causing premature wear. Another example would be in scraper applications where due to the deeper lug of the R-1W in the high torque hard surface application the taller lug tends to be more unstable and flex causing lugs to sometimes be torn from the tire.

Up until now there has not been an R-1 choice for operators on the larger volume tires for larger tractors in the more arid regions, scraper applications or larger floater options for sprayers. The entire market has been R-1W’s. Titan is introducing the Optitorque Radial R-1 line expansion coming out with the 710/70R42 and 800/70R38 sizes for those operators and applications that an R-1 will outperform the R-1W. At the end of the day it really is up to the end user to determine the conditions he is running in and determine what tire they should be using and what will work best for them. They also need to make sure when comparing tires and tire brands, some may be comparing an R-1 to an R-1W , the good news is now at least, they will have more choices.

Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

Originally, the standard pattern was the “R-1” type and the “R-1W” (“W” stands for “wet”) was seen as the specialist for wet soil types with approximately 20% more tread depth. Between 1950 and 1975, developments were made in the agricultural tire business, such as the standard fishbone pattern and the radial agriculture tire. During this time, the “W” type became more popular and the preferred type for many farmers around the world. Today in many regions, the R1-W is the “standard” pattern with some tire lines only available in the R-1W pattern.

A reason for the R-1W preference may be that farmers expect 20% deeper tread to provide a 20% longer lifetime. Additionally, due to the more aggressive pattern, they may expect higher traction on the field.

With improved tire technologies and changes in operation today, this logic is not quite valid. From a wear perspective, the individual tread design and compound properties are much more important than the difference between R-1 and R-1W. For example:

  • Comparing R-1 and R-1W, the deeper tread patterns often have smaller lugs, so the amount of rubber material withstanding wear is often the same on both tread types. In the end, this should result in comparable lifetime.
  • To have proper self-cleaning with heavy soil types in combination with deeper tread, the distance between lugs needs to be greater. This also reduces the amount of rubber withstanding wear on the R-1W types.

The amount of road transportation and transport speeds have increased during the past 20 years. On the road, the R-1 can have the advantage:

  • On average, they have a wider lug surface making contact with the road/hard ground which allows a better force transfer.
  • Lower lugs allow better intersection of the lug front on the road without trouble for self-cleaning on the field. This allows tire designers to optimize rolling comfort properties with less limitations, such as noise and vibration.

Of course, tractors are mainly designed to work on the field and less on the road. So, let´s look at the differences between R-1 and R-1W in field applications.

Soil types are quite individual. Even the same soil type can have different characteristics depending on the thickness of different soil layers, the distance to harder underground layers, and individual and changing weather conditions that impact humidity content. A general recommendation for R-1 or R-1W based only on soil type cannot be made.

As the “W” for “wet” says, 20% more tread depth shows significant traction advantages, especially on wet soil types where the lugs sink completely into soil. This additional traction is only given if the soil between the lugs is compressed properly though. If the soil is too dry, or the ground underneath the loose soil is too hard, the compression of the loose material won’t occur in the interlug section. In this situation, a lower tread depth will compress the soil a little bit more allowing additional traction force to be transferred, like the following picture displays.

Recommendations for Farmers

Lifting the implement, driving over an exemplary soil area and “reading” the imprints of the tire from time to time can tell farmers about the situation of the “gear-pairing” between their specific soil condition and tires. This builds up expertise for the next tire selection.

If the traction forces don’t deem an advantage of one type over the other, consider the increased risk for wrinkles in the connection between the lug and tread base associated with higher lugs.

Another factor that needs to be considered for the choice between R-1 and R-1W is the application. On many soil types, especially when wet, the “W” type can generate better traction. But for many applications, the traction is not the limiting factor, such as seeding applications or PTO-driven implements. Here a wider and more even footprint of the R-1 or even a partly worn tire causes less impact to the soil, which needs to be eliminated by the implement.

One quite special and sensitive application is the grassland operation where deep and sharp lugs can cut the turf surface. The effects from this may make the track areas unusable if mud or earth could be picked up in the silage and harm the fermentation. The right tread design and tread depth is very important here.

A good example to always use the optimum tread depth is practiced in the Netherlands. They have an active sale and resale market with realistic prices for used tires. In wet soil areas for tillage and ploughing, new R-1W tires with less than 50% wear can be used. Afterwards the partly worn-down tires are welcome to be sold in their wide areas of grassland farming with wet surface conditions that are highly sensitive. They are used in this grassland application until worn down completely.

Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

First what is a R-1, R-1W, R-2, HF-1, F-2 etc.? It defines the tread pattern of each tire and follows norms/rules established by TRA (USA) and ETRTO (Europe). R-1 and R-1W are the tread patterns used mainly for traction in agriculture and is the typical lug type design. The main difference – defined by norms – is that the lug of an R-1W tire is 20% taller than the lug of an R-1. R-1W is an evolution of the R-1 that started in Europe as the soil conditions there are normally more humid than in the U.S. From there the W in R-1W means WET.

Trelleborg Progressive Traction

Each tire manufacturer has it’s own lug design (width, length, angle, shape, quantity) and follows his experience and development to provide the best traction capabilities in each soil condition. Trelleborg with the exclusive Progressive Traction (PT) line up adds an additional small lug in the base of the normal lug providing an additional anchor point. The result is an improvement in traction increasing the power transfer from the transmission to the soil. This wider lug base also increases the damage resistance of the lug.

Most Europe based tire manufacturers – as Trelleborg – offer a complete Radial R-1W (WET) lineup, combined with the flexible sidewall tire construction, that deliver a flatter tread profile than conventional R-1 tread pattern. This design provides a larger footprint on the ground, with more and longer lugs contacting the soil at the same time and deeper into the soil. This provides a higher traction (less slippage, less fuel consumption) and lower compaction on the soil compared to R-1.

Having a tire that can perform under wetter condition without compromising performance expands the working window available for each job.  Also, another advantage of R-1W is as the lugs are 20% taller and a flatter profile, the tire has a longer and more even lug wear life as conventional R-1.

There are some cases where a R-1 lug height design performs better than a R-1W. This is the case with sprayers and spreaders. This equipment is traveling at high speed with full load on the road (hard surface) where all the pressure is on the lugs only. This high lug movement on hard soil generates higher amount of heat (worst enemy for tires) accelerating the wear of the lugs. In this specific case the tire manufacturer created sprayer specific series (Trelleborg with TM150) with a R-1 lug design height, but increased the number of lugs. This concept allows the load to be distributed on more lugs and generates less heat with faster dissipation.

Finally, it has been a custom to use the R-2 design (taller lugs) in muddy conditions like in rice fields. The traction performance and grip are superior in these muddy field but was not adequate at all for not so muddy soil condition or road transport. The lugs would suffer high stress, bend with higher damage possibility, higher wear and very uncomfortable ride. Trelleborg in order to offer an alternative to these conditions has developed and launch recently to the US market the 480/80R50 TM600 Rice PT with a new and innovative R-1W+ profile. These lugs of these tires are taller than the “normal” R-1W but shorter than a R-2, combining the positive aspects of both tread pattern (R-1W and R-2) and the exclusive Progressive Traction concept from Trelleborg.

In sum, always think about the specific application when choosing whether to use R-1 or R-1W.

CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

Why would a dealer recommend an R-1W over an R-1? Why would a farmer buy either one?

The difference between the R-1 and R-1W is the tread depth. The “W” designation stands for “Wet” and has approximately 25% deeper tread depth. Remember this is an approximate! The reality is that when comparing tread depths between different product lines from the same manufacturer or from different manufacturers, there are most likely other design differences than just the depth of the tread. These differences should be a primary concern in the buying or selling process. Tread depth should be a secondary concern.

The primary objective should be to identify the best product for the application, period! Making the best choice can only be achieved by identifying the application as well as the features and benefits that are needed or required. Does the specific application require increased load carrying capacities, high speed capabilities, maximized traction, flotation . . . or does it just need to hold air for the application? The application and features required should drive you to the best product. The answers may lead you to bias, radial, high speed, flotation, row crop, IF, VF or even IF CFO product lines, among others.

In the majority of cases, multiple tread depths are unlikely to be a factor in making the purchasing decision.

Comparing the various options based on a cost per 32nd of tread depth helps with cost comparisons. The R-1’s will cost less due to reduced tread depths which translates to less rubber in the tire. Don’t get caught pricing a “tire” against another “tire” without the details or you may get caught appearing to be out of the market price-wise!

Tread depths can enter in the buying decision where the equipment is only operating in dry conditions or is not utilized in applications requiring maximum power to the ground, or other high-performance features.

No farmer plans to operate their equipment in wet, muddy conditions but when they have to, they would be better served with R-1W’s over R-1’s due to the additional traction the deeper lugs can provide. Dry conditions either stay dry or go to wet and wet conditions only stay the same or go towards the dry side with time. Amazing! It’s much better to be prepared with the deeper tread depth radial tires for wet conditions because down time during harvest season can really hurt the bottom line.

If you are comparing costs of an R-1 vs an R-1W you should see at least a 25% price gap to seriously consider the R1. The R-1W has about 25% more tread depth and in the majority of applications, the increased tread depths will deliver a longer service life that will correspond with the increased tread depth percentage. Keep in mind when you start with an R-1W you can run the tires for quite some time and with the right amount of tread removal, you will then have your R-1.

If pricing is the only consideration, then the cheaper the better. But the cheapest tire may end up being the most expensive in the long run. We tend to get what we pay for.

What is the best buy? It is very simple . . . the correct tire for the application and operation. The tire that provides the performance and trouble-free service life that fits the farmer’s needs is by far the best option.

Just keep in mind . . . a deeper treaded R-1W might provide a bit of insurance against wet conditions when it is needed the most!

Dave Paulk: Manager Field Technical Services

Before the R-1W was introduced to the U.S., there was an R-1 and R-2. The R-1 was designed for general farming, while the R-2 was designed for extremely wet conditions such as with rice and sugar cane (Rice and Cane tire). These tires were used before radials were popular and bias tires were most common.

As equipment got larger and heavier and farming practices changed, bias tires gave way to radial farm tires in most types of farming. Radial tires are designed to carry heavier loads at less air pressure and generally last longer when they are driven on the highway. Because of the body construction, bias tires have a tendency to squirm and wear out quicker when run on the road.

The R-1W was originally designed as a fit between the R-1 and the R-2. The R-1W has approximately 20% deeper tread than an R-1 and 20% less tread than the R-2. With today’s tire and compounding technology for radials, the R-1W is used where both the R-1 and R-2 were used with bias tires.

The R-1 is designed for general farming in dry dirt as the tread depth is not as deep. The R-1W is also used in this application and has a 20% deeper tread, providing a longer tire life. This is important because farms are now scattered and tractors must be transported on highways to move between farms.

R-2’s were designed for muddy conditions and is still the tire of choice for crop such as rice, cane, and vegetables in irrigated soil. In some of these conditions, the R-1W is used where the dirt is wet, but not muddy. The R-2 does not do well when they are driven on the road because the lugs are deep, bend easily, and can develop uneven tread wear.

The R-1W is a good all-around tire to use for general farming practices. BKT makes this tire with a 45-degree angle that does well in the field and rides and wears well on the highway. The extra tread depth gives it longer wear and more value for the money paid.

Radials in general are better than bias tires where soil compaction is a concern because they can be run at lower air pressures with higher load carrying capacities to lessen soil compaction. BKT radials are designed with a flatter footprint to distribute weight evenly. BKT also makes tires in the IF and VF design to lessen soil compaction where needed. The IF carries 20% more weight at the same air pressure as a standard tire and the VF carries 40% more weight at the same air pressure as a standard tire. Less air pressure equals less soil compaction, producing better crops.

Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

R-1W tires have taken the farm tire market by storm, and it’s no mystery why. Just a few years ago, these extra-deep-lug farm tires were super-premium offerings, reserved for the biggest tractors and the largest farmers. Now, most of the top tire manufacturers have R-1W tires, prices have come down, and the deep-lug technology is within reach of most farmers.

When it comes to extra traction, heavy loads, and lots of torque, R-1W tires are the way to go.

Think of an R-1W as a classic R-1 directional tractor lug tire plus 20 percent more depth. The “W” in “R-1W” actually stands for “wet,” to indicate its increase in wet traction versus a traditional R-1. That’s perfect for Midwestern or Southern soils—gumbo soils or sandy loam where you want more bite. That R-1W lug is going to grab more earth and propel the tractor forward more effectively, while the area between the lugs keeps the tire on the surface of the soil.

And nowadays, with fields spread farther apart, it’s nice to have some more rubber to extend tire life on equipment that spends more time on the road. Beyond the extra depth, today’s R-1W tires also have better compounding than ever, which is great for longevity.

That said, sometimes all a farmer needs is a good, classic R-1. Say you’ve got a small chore tractor in your equipment yard—70 horsepower, loader on the front or a box scraper on the back—that doesn’t even leave the farm. You don’t need an extra-deep lug tearing up the ground for that. And if you’ve got a tractor that’s just pulling a tedder and a baler around a hay field, you don’t need the added expense of an R-1W. Basically, you’re not going to wear out that R-1 tire on a haying operation, so why pay more for extra tread you’re not going to use?

Another situation where it may be better to stick with R-1 tread rather than going to R-1W is on a high-clearance sprayer. The deeper R-1W lugs on a 380/90R46 tire will squirm more than the shallower ones on an R-1 of the same size. Obviously, that’s a disadvantage when you’re trying to run straight between the rows or steer a few thousand pounds of spray solution down the road. The R-1 will give you a more stable ride and build up less heat on the road between fields. Definitely a better choice for that application.

On the other hand, sometimes you want even more lug than an R-1W can deliver. In the muddy fields of rice and sugar cane in the South or sugar beets in the North, some farmers invest in R-2 tires, which have massive lugs more than 3 inches deep.

An R-2 tire works differently than R-1 and R-1W tires do. Instead of floating the tractor or combine up on the surface of the soil and reaching in for traction, R-2 lugs actually dig deep and scrape a layer of mud off the surface, clawing for drier soil below where they can get traction. The angle and lug design are extremely aggressive—more aggressive than you’d want in a drier field, especially if you are trying to stick to minimum tillage or no-till.

Working with a tire dealer in Arkansas, Alliance just designed a revolutionary R-2 tire. Our new Agristar 374 R-2 tire delivers great traction, excellent self-cleaning—which is vital to keep tires from turning into clay-coated racing slicks after their first rotation in heavy, wet soils—and outstanding performance on the road. The old R-2 standards that have been on the market since the ’60s are poor performers on the road: the deep lugs gave a bouncy ride, and because they were so tall, they tended to squirm a lot. That also built up a lot of heat, which, as we know, is a sure way to kill a tire.

We completely redesigned the lug on our new R-2 tire. It’s deep—105/32″—but we’ve built it with a stair-step-style construction, tapered out at the bottom and anchored to a lug bar in the center of the tire to minimize squirm. Those truncated stair-step shapes also provide more biting edges in the mud for extra traction, and a wide nose on each lug smooths out the ride and improves steering even further. And everything about the sidewalls enhances the tire’s performance, from enhanced heat dissipation to extra flex that maintains a flatter, more even footprint for better traction and longer road wear.

So if you look at the variety of lug tractor/combine tires on the market—from standard R-1s to the extra 20 percent depth of an R-1W to the massive R-2 that is a full 3 inches deep—you can really take your pick of the tire that’s going to deliver the performance you’re looking for…and paying for.

Precision Inflation, LLC
Ken Brodbeck, Vice President of Technology

When should a user select a R-1 or R-1W? See the comparisons below:

R-1W over R-1:

  1. 20% more life, especially if the machine does a significant amount of road travel.
  2. Better tractor resale value.
  3. Minor loss in traction over R-1 on firm dry soils.
  4. Minor traction advantage in wet muddy conditions.
  5. Eventually R-1W will become an R-1 tread after roughly 1000 hours.
  6. Rear Sizes over 80” in diameter are only offered in R-1W.
  7. Soil Compaction is directly related to tire pressure. R-1 and R-1W use the same load/pressure table. To minimize compaction, know your axle load and set the tires to the minimum pressure required by the tire manufacturer and check weekly. If you do not check tire pressures regularly, you should run 2 to 3 psi higher than the minimum to protect your tire investment.

R-1 over R-1W:

  1. R-1 bias and radial are usually the lowest cost tires for low hour use tractors.
  2. R1 treads are the favorite for most tractor pullers due to better grip on hard pulling tracks.
  3. Think of a high horse power tractor puller using a slick with ¼” high tread bars. They win on firm tracks!
  4. Older lower horsepower sizes may only come in R-1 tread.
  5. Soil compaction, see point #7 above.

What about R-2 – Rice and Cane Tread?

  1. R-2 tires work well in true mud with a solid plow pan.
  2. In mud without a plow pan, you quickly bury the machine.
  3. R-2 tires are expensive, rough riding on pavement and do not pull as well in normal moisture soils.
  4. How about for “insurance in wet harvests?” You will probably be better off buying a large flotation size to keep tire pressure low and float over the soft spots.

Michelin Ag
David Graden: Operational Market Manager – Agriculture

R-1 and R-1W are tread designations used to describe a tire tread bar typically a corresponding usage. Most common designations found are R-1, R-1W, R-2, etc.

R-1 is a standard tread and typically used in applications that demand very little from the tire. For example, you may find an R-1 lug tire in dry farming or on general purpose chore tractors. And in some applications, conditions need to be ideal.

R-1W is typically considered a wet traction tire for use in softer soils. This lug design can have larger voids between lugs and deeper lugs than an R-1. These tires are also considered a deep tread or premium option for most tire manufacturers.

Here at Michelin AG, we only make R-1W tires. When it comes to putting more horsepower to the ground and improving traction in your less than ideal everyday conditions, let’s be honest. Think spring planting. No one has the luxury of working in ideal conditions. The standard R-1 just isn’t enough.

Take a look at the lugs on your AG tires next time you get the chance. What you will notice is an almost A-framed design, sweeping up at an angle from the front and the same angle back down along the trailing side. The basic reason for this type of lug design is stability. Unfortunately, as this type of lug wears, the biting edges will round over and eventually create a lug that resembles an angled bump instead of a tread bar.

The standard Michelin R-1W, however, will maintain those biting edges and deliver exceptional traction when up to 70% worn with up to an additional 50% tread life. The Michelin lug design is really to blame for this exceptional performance. Not only do Michelin rubber compounds tend to wear slower, but more rubber tends to bring longer tire life. Additionally, the upright nature of Michelin lugs leaves a very consistent shape throughout the entire life of the tire. This translates to traction, which in turn, burns less fuel by operating more efficiently.

Finally, since R-1W is the designation for all Michelin AG tires, our standard tire pricing isn’t far off from our competitor’s standard tire pricing. Meaning, you could purchase a Michelin Agribib 2 for a very comparable price as our leading competitor’s standard tire. The difference is you are getting much more tire at an even better price with Michelin. After a few years, you’ll have an R-1.

Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

When choosing to place radial traction tires on a tractor, one of the most common questions we hear is whether R-1 or R-1W tires are best. When looking at the price difference between the two tire types, farmers wonder what they get for the higher price of an R-1W. To help farmers make the most informed decision, here are some facts and performance benefits for R-1 and R-1W tires.

The language itself, R-1 and R-1W, is a tire industry standard defining the minimum designed tread depth of an agricultural traction tire. The Tire and Rim Association defines the minimum bar height based on the tire width and the aspect ratio (height of the sidewall). The R-1 designation is the standard tread depth. The tread depth of an R-1W tire is at least 20 percent deeper than the same sized R-1 tire. In simple terms, R-1W tires have a taller bar height, but all the other dimensions, such as overall diameter and rated load capacity, are the same between the R-1 and R-1W tires.

There is not a substantial performance difference between the two types of tires – particularly for farmers who are concerned about soil compaction. Soil compaction is the result of the axle load and the inflation pressure to carry the axle load. Since the two tires have the same load and inflation pressure, the tires will create the same amount of soil compaction. If farmers are concerned about soil compaction, it is more important to look at tire sizes or IF and VF tires that carry the axle loads of their tractors at pressures below 15 psi.

  1. The traction difference between the two tires depends on the soil conditions in which the tires operate. The deeper R-1W tread depth does not automatically mean the tire has more traction. Traction is dependent on tread bar shape and the angle of the bars. However, when deciding between the types of tires, pay close attention to soil conditions and consider the following:
    Dry or normal soil moistures can use an R-1 tire. The R-1 and R-1W tires will have similar amounts of traction. Both tires work great in these soils, but if a farmer is debating the two tires because of cost vs. performance, the R-1 tire is more cost efficient.
  2. In wetter soil conditions, even if they are borderline, consider using an R-1W tire. Just like in dry soils, the R-1W tire doesn’t generate more traction over the R-1, but the deeper skid will help maintain traction in higher slip ranges. The extra cost of the R-1W helps ensure traction in those areas, which helps with time and fuel efficiency.
  3. In wet soils, like those in the Texas Bayou or the Gulf Coast region, neither the R-1W or the R-1 are the best choice. Instead, farmers could look to move up to an even deeper tread on R-2 tires. The tread depth of an R-2 tire is two times deeper than R-1 tires to help gain traction in those wet soils.

After considering the soil conditions, think through how often the tractor will be running on paved surfaces like the roads or concrete feedlots. If a farmer doesn’t have to drive many miles on the road to get to their fields or doesn’t operate in a concrete feed lot, then an R-1 tire is a good, cost effective solution. If a farmer does travel long distances to get to their fields, or if the tractor operates in concrete feedlots, move to an R-1W tire. The deep skid will allow the farmer to put more hours on the tractor before the tires need replaced.

Above all, consult with your local tire dealer to determine what type of tire works best in your area. It’s not always necessary to move to a more expensive type of tire based on traction or performance claims. If the conditions allow it, sticking with an R-1 tire may be a way to reduce costs in equipment maintenance.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

Can BIAS Tires Beat Radials? 2018-12-01T21:11:43Z  


Can old school 1930’s Bias Ply Technology provide better traction than latest High Tech Radial?

The short answer is YES!

I don’t believe it, you say.  Surely these high tech radials must always out-pull Dad’s Old Bias tires, right?

The answer depends on your tire pressure!

When your New Radial’s air pressure is matched to the axle load, they will always out-pull their Bias counterpart. But if the Radial is over inflated, the Bias tire with the correct air pressure will probably win.

The sad truth is many farmers over inflate their tires for various reasons:

  • Tire Looks Low.
  • The Tire Changer Erred on the Safe Side:  tires were set at 25 psi and may only need 12 psi.
  • Tires were Inflated for a Heavy 3 or 2 Point Implement or Planter, then not deflated for a disk or pull type ripper.

OK, sounds reasonable, but has anyone ever tested Bias vs. Radial head to head?

Yes!  In my career at a major agricultural tire manufacturer, we tested a new Bias vs new Radial with the exact same tread pattern to confirm.

The tractor was a 4WD hooked to a load unit that measured pull and slip in real field conditions.


Correct inflation was 12 psi for both tires.

The results were what you would expect.  With both tires at 12 psi, the Radial out-pulled the Bias by 7 to 9%.

We then over-inflated the radials to a typical field pressure of 20 psi.

The 12 psi BIAS tire BEAT the 20 psi RADIAL!

What does this test mean for you and your tractor?

If you are running over-inflated radials, you are probably:

  1. Burning More FUEL
  2. Seeing More TIRE SLIP
  3. Creating More SOIL COMPACTION that can reduce yields.
  4. Creating Deeper RUTS in soft fields.

My advice, contact your local tire dealer to properly set your tire pressures, unleashing all of the benefits your new new age high tech radial AG Tires can provide.

When you do, your wheel tractor will probably give the track tractor a run for its money!

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

Ken Brodbeck is an Ag Engineer who spent 35 years at a major ag tire manufacturer. He is now Co-Owner of Precision Inflation, LLC, an Independent Dealer for German PTG Inflation Systems for Agricultural Machinery.