Im look to get some new tires pretty soon and I currently have the continental extreme contact 275/40/17 in rota rb's 9.5 wide I was wondering if I could fit a 315 tire in the 9.5 wide rim because I have a friend who's got a 2011 gt500 cobra and says he's got a 315 on a 9.5 inch rim anyone done this? Or can anyone suggest a good tire for me?