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Old 02-10-2024, 10:51 AM   #28 (permalink)
aerohead
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wheel size vs HWY mpg

Quote:
Originally Posted by Phase View Post
People claim that bigger and heavier wheels help with highway gas mileage because of inertia

If that’s true, then why are all of the epa highway numbers better with trims that have smaller wheels? Wouldn’t just the city mpg be better and the highway mpg be worse?

So are bigger wheels better or worse for highway mpg?
I've only seen the argument that, the 'smaller' wheel/tire combo is better aerodynamically, with lower 'windage'/ ventilation drag.
EXAMPLE:
Hyundai IONIQ 6 SEL & Limited, with 20" wheels = Cd 0.246
Hyundai IONIQ 6 SE, with 18" wheels = Cd 0. 219
A 12.3% difference in Cd.
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One of our members is presently experiencing range loss on his Genesis GV60, because of the 'larger' wheel/tire combo.
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The 'slightly-convex', 'closed' wheels on GM's 1987 Sunraycer demonstrated zero ventilation drag at all, at crosswind ( yaw ) angles below 15-degrees.
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Last edited by aerohead; 02-10-2024 at 10:54 AM.. Reason: correction
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