My advise, coming from a Viper pilot, is to ditch the run flats and run the viper-spec ps2s. Vipers get special tread compounds. Call tire rack or JonB (viper tire specialist) for the correct ones. A lot of viper racers, however, are switching to others brands like Kumhos since Michelin no longer sponsors our ViperDays races. Hoosiers seem to be the hottest track tire, but many still like the Pilot sport Cup. I've been running the cups for a while, but am going to try Toyo or Kumho next.