I am actually not sure. I run rubber a lot here at my carpet track, but then in the fall Cleveland fever hits and everyone runs foam. I just got a Schumacher Mission recently, and haven't had a chance to run foam with it, but from my previous experiences with foam, it kicks ass. It is so much easier to dial in your car with tons of traction. Want to go to a big race that runs foam? US Indoor Champs in Cleveland.