Quote:
Originally Posted by westygo
Has anyone quantified tire width impact on FE?
Currently looking at tires and rims. Would like to go about 7% larger circumference both to get my speedometer more accurate and to effectively get taller gearing in my 98 Odyssey. It's a 2.3L 4 cylinder v-tec and it revs a bit under 3000 rpm at 100km/hr.
I could go with more rubber (taller tires) or more rim. More rim helps with rotating mass and unsprung weight, but the skinniest tires I can find are 215's for a 18" rim, whereas if I went with 16" rims I could get 205's but take the hit on weight (and looks).
Thoughts?
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Are you trying to go heavier or lighter?
My personal experience has been with swapping from 17" wheels that were fairly aerodynamic and weighed 48 pounds with tire down to 16" wheels that are not aerodynamic and weighed 36 pounds with tire. Overall, the smaller wheels are more pleasant to drive with, the car accelerates easier and faster, and braking is noticeably better(much appreciated!) too! When I went to 16" wheels I also went with dedicated LRR tires, the Bridgestone Ecopia EP422+. Highway fuel economy has stayed the same, and lower speed coasting has improved slightly. I went from 215/50/17 tires down to 205/60/16 tires.
I also found 11 pound 15" rims a while ago that would fit my car, so when I need new tires(assuming I keep the car that long), i'll be going down to a 205/65/15. My current 16" rims weigh 16 pounds each, and the 17"ers were 23.5 pounds.
There are those on this forum that will say a wider tire will give you less rolling resistance, which I find hard to believe, and haven't seen any information on why that is.