Originally Posted by azian21485
even if 15 inch rims weighed the same as 18 inch rims: with 18's, the weight is distributed further towards the outside of the wheel increasing rotational inertia (i think this is what it's called)...so basically, since the weight is distributed farther away from the center, it still requires more torque to accelerate and decellerate
I don't think you'd notice much difference there unless you're talking about some serious weight differences. Lighter is better regardless of rim diameter due to the rebound on bumps being much more responsive. (better handling) The biggest difference comes when the overall diameter of the tire is changed, because you're effectively changing the gear ratio.