My car is running PI wheels, 12x17's, with 335x35x17 rear tires (just about as wide as they make, I THINK there's a 245 out there, but I'm running as wide a tire as is available).
I think it's totally cool that so much meat can fit within the stock fenderwells without mods.
Fronts of course are much smaller, 235x45x17 I think. My car is running on "cheater slicks", basically slick racing tires with just two little rings that apparently make them street legal. No good for rain though, although I'd NEVER drive my car in the rain, for many reasons. It's rust free, and I want to keep it that way.