I got to tell you, these things are AWESOME!! I had 245/50/16 Cooper Zeon ZPT, and my car would spin them through 1st, 2nd and 3rd, I could not launch at anything above idle. Now with the 275/50/15 M/T, I can launch at 2000 rpm and the car feels like it wants to lift off the ground. I didn’t even heat them up, and I had them at 30 psi. Dropped the psi to around 16 and 2500 rpm launches where possible, I couldn’t even do a burnout without water. Clearance is very tight, even with the quad shock flipped around there is maybe ½ inch of clearance between the quad shock and tire. Sorry for incoherent rant, but I forgot how much fun it was to have traction. I can't wait to see how they hook at the track with a nice burnout and some VHT, any guesses?