You guys all drive too damn soft. 18,500 miles and 3rd set will be on before I get to 19,000. Fronts go first, as they should in a road race car. C4C5Specialist, rebalance at 6000? Heck, they are about all gone by that time. Like they say, "Drive it like you stole it!"
I believe I still hold the record for the shortest amount of miles. We went to an Evolution Autocross school in NW Indiana last May. It was on the roughest, sharpest pavement I have ever seen. Worse than the seashell pavement in Florida. We had 155 runs on a new set of rear tires and corded them. That was less than 128 miles. Good program, bad location. Because of Heavy autocross usage, we have never had more than 1800 miles on a set of F1's. Went to Hoosiers, their cheaper and last just as long.