MPG with bigger wheels

[Shift_Altima]

Does your MPG go down with bigger wheels? I'm going from 16 to 18. Will it decrease/

[LongBeachCoupe]

has nothing to do with size.. but WEIGHT is the concern... more weight=less mpgIf you get some 18" rays it will increase the throttle response, if you get stealies it will decrease...

[wild willy]

You know....I seem to remember a show I watched that touched on this subject. I believe they said that the larger wheels did slow down the car a bit even though they were lighter...It had someting to do with rotational mass or something.....

Keep in mind, that unless you maintain OEM circm. your ODO will be off as will your mpg

[LongBeachCoupe]

I dont see how a lighter wheel can slow a car down, unless you are talking about something as specific as wind resistance against a larger wheel or something...

[wild willy]

That was what I thought as well......But the show and the car they were testing proved differently on the Dyno

This was a couple yrs ago....

[generic808]

All that really matters is the overall wheel/tire diameter. If you go with 18's and run 235/45/18 tires, the total wheel/tire diameter will stay exactly the same, not affecting mileage much at all. You may lose a very minute amount due to rotational mass with wider tires though.

[Darius]

Technically, it is the polar moment of inertia of the wheel that determines its resistance to rolling. For the layman and all practical purposes, the lighter the wheel, the better the gas mileage and suspension handling/tunability.

If you have a larger overall diameter, the speedo will read lower, which means the odometer will read lower which will make you think you're getting worse gas mileage unless you account for the larger circumference(%). My opinion is that you will hardly notice a difference. Even if you do notice a decrease, it will be worth it because you will have a better looking wheel/tire combo.

[LongBeachCoupe]

Ahh... now im on 20"s with a 35 profile tire... so what is the multiple of the MPG that the car reads in comparison to the actual? Its like a 2% difference (my car shows X mpg, and i actually get X*1.02 aprox) am i right?

[Darius]

It all depends on the individual setup for the percentage, but yes you are right in your calculation.

[LongBeachCoupe]

yeah... i got a 3.7% overage on a stepup from the 16s to 245/35/20.... so when i get 22mpg its really 22.8 woohoo! now we are cookin!

[windhaven]

No change on my front: Stock 17"'s to 19"'s.

-- Wind

[R1Wolf]

I haven't seen any change with my 19's running a 245/35-19.