How many miles till your stocks were completely burned? I have an 03 silverstone with 9000 miles and my potenza's have about half the thread left. I know they are rated at 140AA which is really low but wow, less than 20,000 life is a little low. Haven't raced my Z or really done burnouts. Anybody with better/worse tire life? Would be interesting to see how many miles those tires last. Other types of tires are also welcome.