Thats super quick. I went about 17k on my oem ps2's before i dumped them. I have stock size ad08's on right now and i have about 18k on them with 40% tread left. I commute about 110 miles a day, slide the car often, and drive quite agressively. However, i don't do any burn outs or do any stressful stuff to the car in first.
Are you doing alot of local driving? Maybe your alignment needs to be re-checked.
Peanut Butter Chunky