Originally Posted by Phokus
I get crummy mileage with my 18" TI wheels.
I just popped on my 15" steelies for snow tires and when I picked them up I noticed a good difference between the weights. I didn't have a scale to measure but it was noticeable.
The car feels easier to accelerate too. I promptly went and filled up my gas to see what kind of mpg I get next fill up with the reduced weight in wheels.
I was doing about 28mpg before mixed but with more city. about 34-36 on the highway with one 40mpg highway trip.
It also isn't just about total weight, but where the weight is distributed. If all the weight was in the center of the wheels, they would have less rotational inertia.
But honestly, i thought it was pretty well known that the huge rims with tiny tires are completely moronic from the POV of fuel economy. Unless, you spend a lot of money on really light rims.