I hope you're being sarcastic. My car comes with 265s on an 8 inch wide wheel. I'm running 285s on a 10 inch wheel, and would KILL to run 315s. FUCK.
Well if I dont like the 255s i already have someone who will buy them so its no big deal if they dont work out. Friend on mine has 315 on a 9 and it ate the a lil notch out of the tire so no 315s for sure.