To answer you question, a 12" rim will give you more grip and a 10" will give you more cush. You will drift more with a 12", I think there is more adjustability when dealing with grip with a 10". I use13.00x15 on 10"on 1300lb car with 280hp to the wheels and it grips at 10lb. But at the drags I run 7 to 8lb.