VF480/95R50, VF480/80R50, and VF480/70R54….why are manufacturers offering so many aspect ratio options?
Aspect Ratio
Before we dig in, remember, Middle number of size = Aspect Ratio (% of sidewall height to section width) as shown below. See our Sidewall Identification Page for more info on aspect ratio https://agtiretalk.com/sidewall-identification/
Goodyear Custom Flo Grip LSW 1250/35R46 Sidewall Shown
Optimum Solution for the Application
For this illustration we will used 480 section width VF rated tires:
VF480/95R50 has the largest air chamber; consequently, it can carry the most load with least amount of air pressure. In other words, out of three VF sizes listed, VF480/95R50 will compact soil less than other options. On the flip side, tire also has tallest sidewall; consequently, tire is most likely to create power hop and experience road lope.
VF480/80R50 is the most common out of three sizes listed, having mid-size air chamber and sidewall height, providing both low compaction along with minimal power hop and road lope. In other words, middle aspect ratio in opinion of many provides the best compromise of low compaction and minimal power hop.
VF480/70R54 is the lowest profile offering in comparison. Tire delivers best answer to power hop and road lope issues with low sidewall; however, smallest air chamber lends itself to compacting more.
Important Points
- When making comparisons, make sure you know if tires are Standard, IF, or VF construction. A lower aspect ratio VF tire (VF480/70R54) may compact less at a specific load and speed than higher aspect ratio standard tire (480/80R50).
- 480/95R54 & 480/80R50 have different overall diameters and rolling circumference indexes; consequently, they often times cannot be interchanged on same tractor.
- Choose best tire for the specific application. Some growers prefer lower sidewall tires for sprayer applications to eliminate road lope associated with high speed roading. Conversely, some growers like high aspect ratio tires in harvest applications where power hop caused by draw bar pull is not an issue.
All information provided in this blog to promote thought only. 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.