Originally Posted by Torch_Vert

Define "worse handling"? Short sidewalls have a minor advantage in quicker turn-in, but that's pretty much it. Shorter sidewalls are less predictable at the limits of handling (they tend to break away with less notice, sometimes suddenly) and they're more easily upset by road surface irregularities (when was the last time you drove on a glass smooth road?).

Formula 1 is big business with millions on the line at every event. If "Big sidewalls = worse handling" you can make really big bucks by straightening those guys out:



Low profile rubber is about a LOOK first and foremost. There's not a thing wrong with that, but don't think an identically setup car is going to do better on an autocross course with 20's vs 18's

Originally Posted by artisto

Dude, you're talking F1 compared to a Mustang?

Originally Posted by Mr.Ski

Agreed, Torch Vert. But i did just check the Ford website and the 20 inch rear wheels are standard on both the hardtop and convertable GT500. One thing i could never figure out though are all of the people griping about the weight difference on the 18 vs 20's. I actually weighed the difference in mine from stock bullit 18's to my Shelby CS40's and the difference was only 3 lbs on the fronts and 8 lbs on the rears. Not a big enough difference to grip about, unless we are at the track.

Originally Posted by JCON

There are places who will but you're looking at the cost of a built blown motor for a set of wheels...

Low profile tires in no way creates comfort, anyone who says it does is either lying to themselves or doesn't actually care. It also decreases traction because there is no give in the side wall under torque. Why do you think all race cars have medium to high profile tires?for what it's worth, I wouldn't buy the 20's unless you keep a back up set to use for daily driving. The only thing I regret about selling mine is that I don't have them for parades. Other than that, I love that going of railroad tracks or a bump in the road doesn't make the car shutter anymore. You'd think a crack in the road was a small animal under my wheel.

You need to find someone on 20's and go for a drive.

I guess my ride comfort experience is different coming from VW/Audi sedans to a Mustang.

Originally Posted by Mr.Ski

Why does Shelby, Saleen, and Ford (new GT500) use 20's on those cars? I am putting a set of 20's on my car right now, but i must admit it is mostly for the fact that i couldn't find any 18's that i liked that will clear the Brembo brakes. I figure if all of them are using them, they cant be that bad. Full disclosure, my car is not my DD.

Originally Posted by Torch_Vert

It's an extreme example, sure, but the principles are fully applicable. If low profile rubber produced superior handling across the board as you were claiming, then the most competitive racers with the most riding on handling would surely be taking advantage of it. They aren't. (nor is Nascar, NASA, or even SCCA autocross, except in classes limited to using OE tire/wheel sizes by the rules)

Originally Posted by Andy13186

I think like 95% of ferrari's including enzo, 599 gto , mclaren mp4c, corvette z06's zr1, porsche carerra gt's, vipers, lambos etc use 19's or 20's with low profile tires

One of the reasons for this is that this size wheels can clear much larger rotors and calipers

Originally Posted by Andy13186

...
The weight difference in wheels is not an issue since lower profile tires weigh less than higher profile tires, it cancells it out usually. You have more moment of inertia to overcome with wider wheels because the bulk of the weight is farther out from the center axis.


... Less sidewall flex also makes steering quicker and more responsive. Less flex and she'll break away while cornering with NO notice and then, BAM, you're spun or off the road. Sidewall flex can be felt giving you more control. It also aids in coming off the line without as much wheel spin.