[turbomangt]

I'm not hard on my turbo, don't spin the tires, drive normally so I can't understand why I go through tires like this. I have 85,000 miles, went through 2 sets of stock goodyears and now I'm on a set of Yokohama520, these have 20,000 miles on them now, and I'll be lucky to get anther 5,000 out of them. can someone tell me what is wrong here?