CuriousGeorge
Well-Known Member
I think I know how BMW/MINI got 4 extra miles on the 2023/24 EPA rating. They are so damn light (under 16 pounds measured by me), but also so thin, especially the side walls.
The increase in manufacturer-estimated EPA range from 110 to 114 miles was probably due to reduced aero drag, resulting from replacing the "air buckets" (fog lights) with slits to direct air flow around the front tires. It was almost certainly not due to changing the OEM tires, because a variety were always used.
The shorter the sidewall, the thinner it can be and still adequately resist flex.