Probably the single-most significant appearance and performance modification you can make is a new set of tires and wheels. While the rage today is to shoehorn the biggest wheel and tire combo under your fender, the reality is that a big wheel and skinny sidewall tire may not perform as well as they look.
Perhaps the best compromise between size, cost, and performance is a 17-inch-diameter wheel wearing 45- to 35-series tires. This combo will provide a reasonably comfortable ride while exhibiting good handling and braking characteristics. If you take a look at the best performance cars OEMs are offering today, you'll find that the majority come stock with 17s. We stuck our heads into some tire-store showrooms and high-performance shops to see what the best and baddest new rubber looks like. Then we browsed the gargantuan Web site www.tirerack.com to get price and sizing information as well as actual users' feedback. Tire Rack's Web site features real-world test results on all the performance tires it carries and a really cool section called "The Tire Rack" where you can see what your car will look like if you mounted a set of wheels from the Tire Rack. Vehicle and wheel selection is pretty much limited to late-model new stuff, but the site is being upgraded constantly so check it out.
To get a look at the tire or wheel of your choice, click on the appropriate sidebar below.