I GURANTEE that a 315 on a 10 will hook better than a 275 on a 10, plain and simple, thats what I do, is simple/cheap/effective. When you pay 260.00 for a set of 800.00 R1's, you use them. But like all the other naysayers on this car/project, Thanks. I have ran 245 on 7" rims, sure, its not optimum, but it works. Tell me what saftey hazard they are in, because with my experience, have never had a saftey issue with my tire sizes VS Rim width. I appreciate all feedback, negative or positive.