Weird. I'm going on 23,000miles on my SP9000s. I've rotated them every 5,000 miles or so, somtimes less. They are still in damn good shape. I could probably get another 1000 or 2 on them, but I'm gonna replace them while they are off for the winter. I also lowered my car in April and had it aligned. And aligned again after somebody backed into my fender. My winters have no problems, and they probably have 9,000 miles on them.
Chris
