Autoxed my GXP at a local event yesterday on borrowed 245/35 Kumhos (24.8" diameter) and didn't do so well, the gearing was too short and there just wasn't enough rubber at the back to get the power down. I've been considering the 275/35-18 (25.2") and 295/30 (25.3") Hoosiers and have so far been convinced by Miles at the Tire Rack that the 295s are the best choice. Has anyone ran them? Does anyone have another favorite tire for the GXP? Too bad that the 255/40 R6 doesn't come in an A6 compound because at 26.1 inches it's the tallest choice in an 18 by far