I am just replacing my rear tire at 5500 miles. The main reason is the fact that I picked up a piece of metal dead center in the tread. I don't know if it went deep enough to cut any cords, but since I have a long trip planned (about 3000 miles total) I really don't want to risk it. It isn't leaking any air, but 80 mph is a tough time to find out you have a rear tire problem. I have noticed though that I am getting some cupping on the left side. Right side looks to be normal wear. I am having them double check the alignment while putting on the new tire. I did replace the stick on weights with dyna beads. With the wide profile of the 300 tire, I hope this wasn't a contributing factor. Front tire still looks really good.