What are the biggest tires or wheel and tire combinations to fit on a 2000 Chevy Tracker?

I just need a little extra ground clearance but i don't want to do a lift or coil spring spacers, so I am wondering what the biggest tires or tire and wheel combination that i can put on a stock 2000 Chevy Tracker. Preferably i would just like to do a larger tire if possible.|||http://www.tirerack.com/ This is a great site to find the tires and wheels your looking for.Best of luck.