Wheel Size Effect

[Shaggy]

Okay i will try for road racing Jim is fully correct the less sidewall you have the less there is to flex making a lower profile tire responds quicker to turn in. but going from 17 to 18 can actually hinder road race perfomance because you are hauling more tire and wheel weight and a 275/35/?? is going to have the same height sidewall no matter the rim diameter it will just be one inch overall shorter between a 17 and 18 inch rim so as long as you are geared for that tire height then you will be fine.

Now for drag racing a good drag racing slick/cheater has soft sidewalls to absorb some of the shock on launch look at the tires in this picture




Now this is extreme but that is part of the design becuase of this though there is no real great comprise between a corning tire and a drag tire and that is with out talking about tire growth built into drag slicks either. For drag racing a iwould recomend 15's and for the street i would recomend 17's the main resasons being that the 17's are cheaper and if you want a totasl tire hieght of say 26 inches you get a little more sidewall to protect the rims for potholes.