View Single Post
Old 08-18-2008, 08:21 PM   #11 (permalink)
whokilledthejams
Boxhead
 
whokilledthejams's Avatar
 
Join Date: May 2008
Location: Fredonia, NY
Posts: 322

Boxy Brown - '04 Scion xB
90 day: 35.48 mpg (US)
Thanks: 0
Thanked 1 Time in 1 Post
Send a message via AIM to whokilledthejams
Quote:
Originally Posted by BetsyBio View Post
I wondering the same thing about wheel weight as I switch from 14in rims in the winter 20in rims in the summer.

What I have found is that I actually get better mileage with the larger rims, but only when driving mainly highway speeds and P&Ging. Because I can coast farther and take turns at faster speeds without using the brakes I think it also helps the mileage because I can put 55psi in the tires as apposed to 35-40psi with the 14 inch rims.

My question is does anyone think that the inertia of the heavier wheels is the main reason I am seeing an improvement in mpg or is it the higher psi in the tires ?
It's probably a combination of the two, as well as the driving you do. If you did a lot of stop-and-go, you'd see better results from smaller, lighter wheels. Really big alloys are extremely heavy, though ricers will swear up and down that the aluminum 18s they put on their beater Accords make them faster, even though they have twice the weight to turn vs. stock steelies.

Also, winter gasoline formulations will tend to make your FE take a hit, too. You might try running a couple of tanks in the summer with your winter wheels as a control.

If you can properly take advantage of the inertia offered by huge wheels, however, then go for it.

__________________
  Reply With Quote