How Does Sidewall Affect Handling?

[JET]

17's will help on turn in, other than that it won't help a lot. Like CVD said, the tires make a much larger difference.

[FattyBoomBatty]

All it does is hold up and support the bumper and making crashing safer.
...for benefit glorious nation kazakhstan.

As for sidewalls, as these guys:
http://www.pictures-of-cars.com/Renault-F1-Car.jpg

[Kracka]

Tire PSI is also a very important consideration along with what actual tire you choose.

[sleepydsm]

Ahh, well then I might just get some better tires for my stock rims. The previous owner did an awesome job PAINTING them gunmetal. I've gotten many compliments on the stock rims, and they're growing on me ;) Not wide enough tho :/

[JET]

Going to a wider wheel was the biggest benefit I have seen. It gets rid of a lot of sidewall flex.

[sleepydsm]

A friend has some black powdercoated FD Rx7 wheels he might want to get rid of...

[Kracka]

Those are light and wide.

[91autoeclipse]

1. I'll go 17's.. but it has to be leight wheels.. can't be more then 18lbs.
2. Better looks.
3. Less sidewall.

Base on this I'll take the 17's