AG TIRE TALK KEY TAKEAWAYS
ASCENSO: “We feel that the Electric Power movement will move directly with the autonomous movement in the future in the larger tractors. As autonomy begins to pick up speed the overall tractor sizes will go smaller, and the Electric Power will be easier to adapt.”
PRECISION INFLATION: “Most likely, in the next 4 to 8 years only 100 hp and under tractors will utilize electric power.”
TRELLEBORG: “Electric Tractors will be used mainly in the yard, feedlots, dairy barns, and poultry areas where distances are short, recharging is available and utility size equipment is required. Vineyard use is another popular application for these tractors.”
YOKOHAMA: “The fundamental challenges to tires are the same across all electric vehicles…the machines deliver very high torque almost immediately—a truly impressive amount of torque. To handle that force, we need extremely strong beads to minimize slipping, reinforced sidewalls, and extremely strong undertread and tie bar construction…”
MICHELIN: “From a tire perspective we can no longer assume that our current rubber compounds and chevron patterns will perform under the torque these electric vehicles can put down…rubber compounds within these tires will need to handle instant torque, without chipping, chunking or tearing apart.”
MAXAM: “Maxam’s Liquid Phase Mixing…enables optimum rubber mixing uniformity during raw material manufacturing…takes our products to a new level of performance and durability capable of delivering improved tire life, lower rolling resistance, and deliver the performance that the heavier electric vehicle loads will require.”
BKT: “Our Electric-Ready Agrimax Factor Tire lug orientation ensures less rolling resistance…the 5% increase in lug length contact area significantly reduces the noise level in the cab.”
Ascenso Tires North America
Annie Boyer: Marketing Manager
We (Ascenso) believe that the growth of Electric Power Vehicles in the Agricultural Tractor Segment will come first in the under 40 hp and then move up from there. This smaller segment will be the easiest to transform from a cost-effective point as well as means of use point, as these tend to be less constant use applications. We feel that the Electric Power movement will move directly with the autonomous movement in the future in the larger tractors. As autonomy begins to pick up speed the overall tractor sizes will go smaller, and the Electric Power will be easier to adapt. On board air will also be standard more and more in the future. Combines and carts will most likely be the last place for EV or autonomous use.
There really won’t be a need for the tires to change in a significant way just due to electric operation. Hybrid treads, those that are a mix of R1/R4/R3 may become more popular just from a noise, roading and a more even compaction area point. The added weight that may come with electric on small tractors will likely require wider and perhaps a little taller tires in the future. There will most likely never be one design that meets all requirements, so there will always be a variety of choices based on specific needs and this fits Ascenso’s plan to build application specific tires.
For skid steer, loader segment just the move to electrification should not cause a direct need to have a different tire. Of course, with all vehicles any weight or overall speed change always affects the tire size or load index required. There could be a redesign coming where the tires will be significantly taller on future skid steer models.
Perhaps the greatest need for the future of electrification of vehicles is from the safety aspect of electrocution- how to safely power and operate these vehicles in harsh environments.
David Graden: Global Account Manager – Agriculture
The challenge here is knowing where this technology will go in the near and long-term futures. If I would guess, we will see electric power adaption to <40Hp Compact and 40<100Hp Utility first, then 100+Hp Med/Large Ag many years down the road or even grow faster in the direction of natural gas and/or hydrogen powered engines. Regardless, the infrastructure for each of these is vastly different from the next, which will ultimately dictate what comes first.
When looking at <40Hp Compact and 40<100 Hp Utility tractors, the infrastructure is already there, in many cases. These machines are typically used for short periods of time and also tend to operate nearer to utilities. In fact, electrification of these machines may not cost as much as one may think, due to fewer parts needed to make them work. From a tire perspective, however, we can no longer assume that our current rubber compounds and chevron patterns will perform under the torque these electric vehicles can put down. You see, whereas diesel/gas powered engines take time to rev up and put power to the ground, electric engine power is instant. This means, rubber compounds within these tires will need to handle instant torque, as well, without chipping, chunking or tearing apart. Hybrid tread designs will help, but unfortunately, the biggest challenge is creating new rubber compounds that perform under instant torque without giving up something else, like tractive capacity, floatation, carrying capacity, etc. For example, when creating a softer rubber compound to perform in winter, you typically give up longevity/mileage in exchange for high tractive capacity. Simply put, the softer rubber moves and changes shape easily, allowing it to grip the ground better and, thus, better traction. At Michelin, we spend an enormous amount of R&D trying to create tires that perform in all environments, however, there is more work to be done.
For agricultural applications, in general, Michelin has historically been an innovation leader. We invented IF/VF tires to carry more load and an industry leading stubble resistant rubber compound that could one day perform quite well in smaller electric machinery. We have also created a ‘shape shifting’ hybrid tread designs that offers lower rolling resistance and improved fuel economy without the sacrifice of tractive capacity and floatation, when used with a central tire inflation system, like Michelin owned PTG systems.
We are all witnessing the beginning stages of time where agricultural innovations are just pouring out of the woodwork! As an industry, we are driven by shrinking land and water availability, every growing food demand and higher than ever energy consumption. As a leading tire manufacturer, it is Michelin’s responsibility to work with our producers to enable them to continue doing what they do best, in the most efficient way possible.
BKT USA, Inc.
Dave Paulk: Manager Field Technical Services
This is a difficult question to answer at this point. With cars, pickups, and trucks coming online, ag tractors will be the next frontier. There are some less than 40 HP electric compact tractors available on the market for light work. Considering all the electric tools now available, from lawn mowers to side by sides, the technology will only get better. Although larger tractors are likely being tested, it appears the less than 40 to 100 HP market is the first seriously being looked at with utility tractors for full electrification. This market will continue to be developed and grow with new ideas. How long will it take to make these tractors where they work well and are affordable?
A look at history gives some insight into the development of modern tractors and the time it has taken to get us where we are today with gasoline and diesel. When you consider that horses and mules were still being used more than tractors through the 1940’s, tractors have made a large jump brought on by technology and the need to replace labor on farms.
From the 1870’s to the 1910’s, steam tractors were used in some areas. The first tractor weighed 14,000 lbs. and produced 30 HP. They could move under their own power, but because of their mechanical complexity, their size, and the constant danger of exploding, they were unusable on most farms. The rate of growth of steam horsepower was far less than the growth in animal horsepower for the time. The first tractors had the same traits as steam engines, as they were heavy with steel wheels or tracks, large, and expensive. By the mid 1930’s several manufacturers had developed general purpose tractors and replacement of the horse and mule had begun. By 1960, except for the deep south, the increase in the percentage of farms with tractors had stopped. As can be seen, it took many years to move from horses and mules to tractors.
At some point, as electrification technology gets better and is used on larger horsepower tractors, tire manufacturers will have to adjust to meet new demands from the equipment. Tire technology now is much better thanks in part to the evolution of MFWD and 4WD tractors. The decreasing number of farmers and the distance traveled between farms has forced tire manufacturers to develop tires that ride smoother and will last longer when used on the highway. Some tractors will now go up to 45 mph. Provisions had to be made and designed to handle those speeds. As electrification advances are made and electric tractors become more common place, advances in tire technology will have to keep up with the demands of the equipment.
If you look at large tractors that are currently used, they are heavy and have high horsepower. They produce a large amount of torque. The industry already produces tires that will handle the weight and stress of high torque. At BKT, tires are currently tested for road noise. Since electric tractors produce little engine noise, this may become a higher priority in the future. Rolling resistance is another issue that is currently being tested. Since tractors spend so much more time on the highway, rolling resistance, ride comfort, and road noise are issues that are at the top when testing. With electric tractors, rolling resistance dictates how long battery life they will have.
Currently, skid steers and loaders are using tires that work for both gas and electricity. Since electric vehicles are heavier because of the battery packs, the tires used must be able to carry the additional weight. This may change in the future with heavier and faster vehicles. Unlike cars, these vehicles travel relatively slowly.
BKT is always looking at market requirements and making changes to accommodate the market and handle the horsepower, torque, and weight of future equipment. As previously stated, BKT already tests for rolling resistance and noise levels. We know this is something being experimented with and are closely monitoring new technology and equipment in the marketplace to supply the best tire possible for these applications.
To service the growing Electrification Equipment Market, BKT has developed a line of E-Ready tires: Agrimax Factor.
The Agrimax Factor lug orientation ensures less rolling resistance. The 5% increase in lug length contact area significantly reduces the noise level in the cab. Both features lead to a greater comfort level. The tire’s braking on wet surfaces is improved. The tires’ strong polyester casing provides good lateral stability and a faster steering response when used in high-speed operations and heavy-duty service. This initial offering of E-Ready tires shows BKT’s commitment to electric mobility.
Precision Inflation Systems
Ken Brodbeck: VP of Technology
What affect will electrification have on tires? Virtually NONE!!
Tractor tires do not care if gas, propane, diesel, or electric power drives the tire/vehicle.
The tractor engineer and customer will still select size, tread pattern, load capacity and set tire pressures in the same way they do with diesel power.
Unlike cars, extra battery weight can be used in place of cast iron ballast.
What tractors will be the first to use electric power tractors?
Most likely, in the next 4 to 8 years only 100 hp and under tractors will utilize electric power.
People need to understand the limitations of batteries vs. diesel fueled engines:
- Pumping several 100 gallons of diesel is far quicker than finding a Tesla supercharger close to any agricultural field. Then waiting an hour or 2 to recharge to 80%.
- Farmers are not going to wait 10 minutes or 10 hours to recharge. TIME IS MONEY especially during planting, spraying harvesting, you understand.
There are several parts of Europe and Western USA where cities have decreed: NO DIESELS only electric or fuel cell.
Several tractor companies make small 100 hp electric tractors where continuous full power is not required, and charging is relatively close or time sensitive.
But for large, time sensitive high horsepower work out in the ag heartland, DIESEL POWER RULES and is the MOST COST EFFECTIVE way to grow food!
Trelleborg Wheel Systems
Chris Neidert: Marketing, Training and Development Manager – AG
I think we can all agree that (electric) battery powered tractors are going to be in some growers’ future. If you read some articles, some will say, “In addition to being cleaner and quieter, an electric tractor is much more efficient, since all the energy goes into work; whereas, in a diesel tractor, much of it is wasted as heat, in addition, maximum torque is available immediately rather than at rated engine speed. Finally, since the power source has just one moving part, they require very little maintenance. Even the batteries are projected to last 10 years, pending operating cycles and depth of discharge.”
Better for the environment and easier on the farmer, electric tractors bring cost savings, reduced maintenance needs and flexibility to growers.
Studies have shown, a typical diesel-powered tractor, using the typical life cycle, emits 53 tons of carbon dioxide every year. A single farmer switching to electric would bring those greenhouse gas emissions to zero.
On average, you can expect to pay around $50,000 to $100,000 for an electric tractor (including economical government incentives). You can also expect to save on upkeep, repairs and, of course, the need for fuel.
But in every situation some benefits come together with some drawbacks. Just what’s involved when using an electric tractor versus traditional diesel? If you’re employing an energy-intensive implement or running the tractor for many hours, you may need to fill up on diesel. Most medium to large farmers work long distance areas, making it difficult to recharge the batteries.
Let’s turn our attention to tires on these electric tractors. I need to lay some groundwork.
Looking into some of the electric tractors that are now on the market, you will notice the overall tractor size and weight is not very high. The main reason is that battery power is needed to move these tractors. So, the heavier the tractor, the bigger the battery required in order to deliver enough working time. With most electric vehicles, the biggest problem is the high weight of the current technology batteries, but tractors need weight for traction, so they would be an ideal electric vehicle.” Some estimates have calculated that for battery power to work in the 250 hp tractor range, a 200-kW strong battery or even more, would be needed. This 200 kW battery pack alone would weight 3 1/2 tons.
Looking at the specs of some current electric tractor in the market, the overall tractor weights are between 5720 to 6700 lbs.
With these lower weights and battery capacities, the applications are somewhat limited. These kinds of tractors will be used mainly in the yard, feedlots, dairy barns, and poultry areas where distances are short, recharging is available and utility size equipment is required. Vineyard use is another popular application for these tractors. High torque applications will be a challenge due to the potential Kilowatt (kW)/Horsepower needed as it relates to the battery size. The current power available for electric tractors in the market is between 40 and 75 kW. Speaking of that, let’s convert Kilowatt (kW) power to Horsepower (hp). We’ll use our example of a 75 kW tractor. That 75 kW on an electric tractor converts to approximately 100 hp on a diesel tractor.
The conversion formula is 1 kW = 1.34 hp.
We will project the max tractor hp to be less than 100 or less than 75 KW.
With these lower tractor weights, smaller tire sizes will be sufficient to carry the tractor weight. We all know that tire size and/or quantity of tires is related to the overall tractor weight. Below are some typical tractor tire sizes that fit the current electric vehicles:
Front = 200/70R16
Rear = 11.2R24
Front = 8” x 18”
Rear = 14.9R24
As you can see, these are on the smaller end of the ag tire size spectrum. With the smaller size, comes less weight. Although we did mention tractor weight is important, with the applications that these electric vehicles will be operating in, heavy vehicle weight is not critical. A lighter vehicle will actually help extend the battery life between charges, due to the battery using less power to actually move the lighter vehicle.
Rolling resistance is a concept used in the automotive industry and will be an additional factor in tires to consider on electric vehicles. Reducing the rolling resistance will extend the battery life between charges as less energy will be “wasted” in moving the tractor.
Tires manufacturer have been working on these aspects redesigning tread pattern, utilizing steel belted construction and new – more environmentally friendly (Trelleborg Blue Tire) – compounds to deliver a lower rolling resistance. This is due to the tire being stiffer which will contribute to reduced rolling resistance.
Tire tread design will be a factor in reducing rolling resistance. A less aggressive tread pattern will be used in the most suitable applications – around the yard, feedlots, dairy barns, poultry areas, vineyard etc., will be a low torque application. Therefore, the tire tread design doesn’t need to be aggressive for a high traction-grip. Looking at the below tread patterns, the one on the left is more of a multi-purpose or all-season tread pattern. Since this type of tractor is not going to be going into the field for long periods of time, the aggressive pattern on the right would not be appropriate.
Electric tractors will be in someone’s future, it may take a while to get to the high horsepower applications, but they are here to stay.
Yokohama Off-Highway Tires America, Inc.
Blaine Cox: National Product Manager—Agriculture, Golf and Turf
There’s a lot of interest in electric tractors across a wide range of sizes, and we as tire manufacturers have to keep up. At Yokohama Off-Highway Tires, we’ve already seen electric equipment coming into the mining, construction, and industrial segments, so we’re building up our base of experience. What we are learning in those markets shows us how electrification will affect the farm not only in tractors, but with electric loaders, skid steers, and other equipment.
The fundamental challenges to tires are the same across all electric vehicles. The first challenge is that the machines deliver very high torque almost immediately—a truly impressive amount of torque. To handle that force, we need extremely strong beads to minimize slipping, reinforced sidewalls, and extremely strong undertread and tie bar construction to minimize the movement of lugs and tread blocks that can create cracking at the base of the lugs.
Electric vehicles also tend to be heavier than their internal combustion counterparts, so high load index is very important. There again, sidewall strength is critical, along with strong beads and the ability to dissipate heat effectively. Expect to see a lot of all-steel construction and improved compounds.
Rolling resistance will continue to be a major factor in tire design—the less rolling resistance a machine encounters, the longer it can work on a charge. It’s just like fuel efficiency in a diesel tractor. Look for high-efficiency tread designs that minimize rolling resistance as well as vibration and noise, which can affect operator comfort, machine wear, and the performance of electronic components.
Electric vehicle technology is a very exciting advance for farmers, and can bring farms to new levels of productivity, efficiency and self-sufficiency. As we have with every shift to new technology—from conventional tires to high-flotation, bias to radial to IF/VF, and new materials—we will help farmers make the most of the opportunity that electric vehicle technology will bring to the market.
Maxam Tire International
Greg Gilland: VP of Global Agriculture
Sustainability and securing alternative energy sources including electrification are driving modern technology developments in compact <40HP tractors up to the larger horsepower platforms. As Tractors represent well over 70% of the global agricultural machinery, the initial developments are focused on the largest and most relevant part of the market. The challenge for tractor manufacturers in converting to electrification or alternative fuels includes the following issues:
- Electric vehicles are heavier as the electric motors are located at the wheelbase and eliminate the need for an axle for conventional engine crankshaft and gearing. This poses an increase in tire weight which contributes to greater potential soil compaction. Currently observed trends on existing electric vehicles in passenger or light truck applications indicate a reduction in tire life of about -30% due to the amount of weight, torque, and power that electric engines can deliver.
- The need for a longer battery service life is ever-increasing. Electrification energy demands are driving battery life improvements to meet the growing market need. Regardless of the power available, the battery service life will be subject to the amount of torque or consumption applied to work a field. It will be difficult at this stage to either have longer recharging cables or portable replacement batteries available to recharge the heavier +150 HP tractor and equivalent machinery that operate in large acreage fields far away from power sources or recharging stations.
- In the absence of long-life battery solutions to meet the torque and field demand requirements, I foresee the ag industry moving down the path of alternative fuels in some segments that maintain the same current engine with multi-axle configurations but with improved environmental or other sustainable capabilities for refueling in the field.
Based on the observed market trends it seems evident the use of electrification or other sustainable fuels may be evolving to the below platforms in the following ways:
- Compact and support tractors below 50 HP represent the greatest immediate opportunity for electric engines and market sustainability solutions. Most of these lower HP engines are primarily used in smaller farming operations, where compaction due to heavier wheelbase weight is less of an issue due to their role as support machinery with limited weight towing requirements. These types of lighter ag applications are less demanding as higher horsepower tractor platform market demands and therefore represent an easier platform to develop short-range or limited battery life offerings capable of evolving into higher HP applications.
- The +50 HP up to 130 HP power range will be the true test of electric developments as these represent the largest global segment of tractors in the market. As tractors above +50 HP are used as production machinery in smaller farms less than 400 acres, dairy operations, or ranching applications, the longevity of battery life and recharging capability to deliver the utility time or productivity required to do the job will be tested. Although increased soil compaction can become a problem in farming use due to the wheelbases potentially becoming heavier, the use of VF tire technology can help offset some of the ground pressure or load requirements to reduce the pressure impact.
- The +125 HP platforms and up to +600 HP 4WD Tractors will be the frontier of alternative fuels or energy as their mission is centered on heavy-duty farming with large fields of more than 400 acres requiring autonomy, fuel range, and power transmission to tow the heaviest pieces of support equipment. The most significant challenge to this equipment is battery life and rechargeability in a remote field application. In the short term, alternative fuels such as methane are delivering realistic and sustainable fuel solutions that consume liquid manure as a source of energy. The CNHI New Holland brand of machinery has already released two platforms in their T6 (+125 to 175 HP) and T7 (+150HP to 300 HP) tractor product offerings that is using methane as the fuel source to power their engines via the consumption of biodegradable animal waste. If battery technology improvements can be achieved, then electrification can deliver the power needed for these larger tractors.
- Light construction equipment that supports farming operations such as skid steers, backhoe loaders, compact wheel loaders, or telehandlers are also evolving into electric or battery-operated platforms. As most of these applications tend to be in hard surface or non-crop impact applications, the heavier electric wheel-base impact is replaced by the ease of use and power transmission, or rim pull. The market test will be the ability of the battery life and recharging time to deliver the utility time or productivity required to do the job. Once again, CNHI Case Construction has already released in 2022, an all-electric backhoe loader for agricultural or municipal applications.
The greatest challenge facing tire manufacturers in the quest for electrification or power sustainability solutions will be the tire weight requirements due to heavier loads and as well the power transmission or torque applied to the tires resulting in reduced tire life as proven by current electric vehicles.
MAXAM is prepared to meet these challenges with two solutions both available and in development to meet the market needs of electrification or sustainable solutions currently in demand:
MAXAM offers VF or very increased flexion tire technology that can carry 40% more load at standard air pressures regardless of the axle load. In most instances, the load challenge of electrification can be solved using VF tires being at standard inflation pressures and able to carry the heavier electric motors without compromising soil conditions or machine productivity. MAXAM has developed VF tires and will engineer additional sizes to meet the future need for ag equipment including tractors, harvesters, floaters, sprayers, and implements.
Solutions in Development:
MAXAM has developed an all-new patented compound technology called liquid phase mixing, coined EcoPoint3 which enables optimum rubber mixing uniformity during raw material manufacturing. The EcoPoint3 compound marks a quantum leap in revolutionizing the performance and durability of MAXAM tires. After years of thorough research and development into high-performance rubber materials, the EcoPoint³ compound takes our products to a new level of performance and durability capable of delivering improved tire life, lower rolling resistance, and deliver the performance that the heavier electric vehicle loads will require. Compared to conventional dry-mixed silica compounds, the EcoPoint³ process provides superior distribution of ingredients in the tire compounding. This complicated process allows products’ masterbatches to contain less filler, higher stress ratio at elongation, and minimum proportions of impurities delivering improved tire life capable of meeting the market demand for sustainability and endurance. The EcoPoint³ technology also represents a breakthrough in green and low-carbon tire development, from the selection of raw materials, manufacturing, and product life cycle, while significantly reducing fuel consumption and carbon emissions. MAXAM will incorporate EcoPoint³ technology into all our new product offerings, including our new industrial, construction, mining, and agricultural standard or VF products.
MAXAM tires are designed to deliver an optimized footprint ensuring the best possible traction and flotation for any application.
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