Sorry I don't know either (which is why I didn't post), but you could measure your tire mounted on the wheel, and then use the equation (rim width) + 2*(cross section)*(aspect ratio) to get a good idea of the diameter of the package you are considering. I've heard of people running 20's with really low profile tires. The SSC's drop our car about 1.7", and I have no idea how much extra clearance there is.