Tire Size
Our Racing Hart rims can handle up to a 225 size tire comfortably. But you are talking about alot of rubber making contact and slowing our cars down while launching. If primarily you would be using the car for autocrossing, this would be a good thing though because you would have more traction in the corneres and slaloms. IMO you should go with 215s, that way you get the enhanced traction without compromising you straight-way speed.