F-150 20” wheels
When I look at Ford’s towing guide for the 2018 F-150 SuperCrew 145” wheelbase 4WD with the 3.5L eco boost twin turbo and 3.55 gear ratio, there are three options: GCWR of 16,100# = 10,700 GCWR of 1...
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BB_TX wrote:Grit dog wrote:
These last 2 posts are false, OP.
It’s not the tires and wheels increasing the capacity unless Ford “chose” to add higher rated tires to the 20s.
Actually in general if the tire OD is the same (unless the 20s are notably taller), the greater the rim diameter, the lesser the sidewall height and the lower the load rating.
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Sorry, not true for all tires. Look at the specs for the Michelin LTX A/T2 tires in LT275/65R18 and LT275/65R20. The 18" tire has a max load rating of 3,415 lbs at 80 psi. The 20' tire has a max load rating of 3,750 lbs at 80 psi. That is 335 lbs more per tire than the 18".
Similarly, the LT245/75R16 tire has a lower rating than the LT245/75R17.
Similar Continental tires have the same load ratings as above for the same sizes.
Don't know about other brands or styles.
Michelin
That’s because they’re not the same height tires. The 20s are 2” taller than the 18s. They have the same sidewall height and greater OD thus more capacity.
I said same diameter tires. Same for the 16 vs 17 example.
Facts. And it’s more about physics than tire construction or brand. Same tire construction, greater width, sidewall, OD generally have greater capacity.
