225's is the max you can put on without rubbing. But see, the optimal rim width is when the rim width is 90% of the tire width. When I put my 225/50/15 on the stock wheels, the tires are about 75-80% of the wheel rim width and that's the minimum... This season I can't afford 17's, so I'll be using the 15's for racing, and 16's for street. Thought next year, I'll be using the 16's for AutoX, 15's for dragstrip, and 17's for the street.
