You would not believe how easily a wheel can become unbalanced. All these cars with 23 and 24 inch wheels must have horrible ride after about 2K. Its hard to believe that every little pot hole you hit effects the performance of your wheels/tires. When I had my SRT-4 if I hit a rather large pot hole or drove on bad roads for a few months I would take it in and have the tires rebalanced. It made a world of difference. When I worked at the shop I balanced my wheels every other weekend. Sometimes the tires would be horribly out of balance while other times they would be right on just as they were the last time I worked on them. I plan on doing the same with my Xfire's wheels/tires. I treat it just like I would an oil change...