Will Larger Rims Decrease Performance?

[ND4SPD]

I heard that if you get larger rims you will lose torque badly but the places I look for rims at say that you will gain more power. which is true? I would think that if you can get a larger set of rims that are about the same weight of the factory ones than you would gain some speed because of the larger circumference would give you more distance in one rotation than the stocks, true?

[Bling]

They will hurt acceleration and braking. Some people say there isn't a noticeable difference though. You will get more distance per rotation, which will probably help gas mileage. It won't help you accelerate any faster b/c the smaller rims are much easier to move than the larger rims due to the weight being closer to the center. SCC did a dyno of a car with different size rims and it made more power w/ the smaller rims.

[ND4SPD]

so how much power would i lose, roughly, if i went with a set of 18 inch rims? a lot? i have a gt and i cannot lose much more

[dragonfrog]

i say **** it. looks better with 18s.... :D if the larger rims hinder the performance at all, i don't think it's at a very large difference. that's with keeping the stock weight on your larger rims. my passion 5's are about 17lbs.

[NoCones]

rim size itself really has nothing to do with it.

rim weight will matter...a heavier wheel is harder to spin and harder for your suspension to control...

rolling circumference of your wheel/tire combo matters, too. go smaller and acceleration improves, but top speed in each gear is lower. go bigger, and, yes, top speeds may increase, but it will take you longer to get there. doesn't really change the "power" of your car...changes the gearing. go bigger or smaller and your speedo is going to be off.

if you can find an 18" wheel/tire combo that weighs similar to OEM and retains the same rolling cirucumference, you probably won't notice a difference (except for the rough ride from the short, stiff sidewalls of the tire)...you will find your wallet to be much, much ligther though...

[dragonfrog]

hehe. that's an excellent response.