Changing Rim Width

[laksman91]

I was wondering if there's a "preformance" increase when using a wider rim, with the same tire. from say 7.5 to 8 inch widths. I think the stock tire for my car is 215/45/18 on the 7.5 width, if i up to 8inch width with the exact same tire would there be more traction?

[aris]

ya their will be more tire..which mean more traction...but also going to a wider rims will slow you down too.

[Hives]

ya their will be more tire..which mean more traction...but also going to a wider rims will slow you down too.

Correct!

[laksman91]

oh yeah aristeidis? could you care to explain? (i just want to know the explanation, not disagreeing or anything)

[3GFX]

Weight.....it all comes down to traction from the increase in tire size and therefore contact patch VERSUS the weight increase from the increase in tire and wheel size.

[laksman91]

well 3GFX, i was considering to use the same tire, so thats a constant, its simply different rims.

[3GFX]

In that case it boils down to rim weight. Despite that half inch differance, the larger rim could still be lighter. It depends on material and construction. With our cars, the differance is not significant enough to warrant a worry. 1 or 2 pounds of weight will not make a large enough differance in the performance of the car. I'd rather have more grip because we all know we can't go fast anyway so might as well make the car stick.

Unless the wider rim is lighter its not going to be better.


One could argue that the stretch of tire over the wider rim will sharpen up resonsiveness because the tire is stretched over a wider rim thus making the sidewall stiffer. I personally don't believe in this since more racing cars have the tire the same width as the rim and rely on a well constructed tire with a stiff sidewall to provide good responsiveness.

To sum up....

If the rim is lighter...its definitly better.

If the rim is not significantly heavier then the tire being stretched could increase the responsiveness of the tire to steering input.