I know that 17in rims are probably the best fit for a 97+ Grand Prix GT or GTP. Just wandering how much width can it be too fit right? 7in, 8in,9in????? Thanks.

The stock wheels are 16x6.5. Alot of aftermarkets are available in XX x 7.0, 7.5, 8.0 which are good size. Try to keep the width of the wheel and tire as close to stock as possible since the combination will weigh less than a huge width combo. Heavy wheels slow you down a good bit.

Tires wider than 8.5 inches may rub the fender during hard turns.