Today I thought I was doing the right thing to get my tires rotated since they hadn't been touched since I bought new tires when I went back to my old Texas home to visit last summer. I found a nice Cooper store and got them rotated, free, by the way, and went on about my business. The car was pulling significantly left, so I went back. They switched them again and I left. The car was then pulling to the right. Damn! So...I went back. Turns out they weren't of equal pressure all around because one of the guy's air gauge was measuring wrong by 7 or 8 pounds. Two guys were doing the rotating, but their gauges were not both accurate. Finally, a supervisor checked them all with his new gauge and found the probem!!
2 days ago