I have 275/40's on the rear on 10's, and 245/45's on the front 8.5. Initially I had 275/35's all round which was just wrong, I had 2 cracked alloys because of those 35's one front one back. Both welded up well, but £320 a wheel was painful. At least I have 2 'if I'm desperate' spares, front and back.