I have the same factory tire on my 21 wrx. Right now I'm at 20k but looking to get new tires for a different wheel setup. I've done the rotations and so far they are okay nothing I would buy myself for $375 each. I'll keep them on the stock wheels so I can put them back on when I sell it.No matter how easily I drive and religiously do the tire rotations I have never been able to do it. The factory tires are a dunlop sport maxx rt and while there isn't a treadwear guarantee, at 9k miles (when a different brand was purchased) the tread is absolutely embarrassing.