The only data Crew Chief uses is what time slip and weather info you give it. It does not data log anything from the car. I like it. It's easy to use. Don Higgins is the guy behind it. Their tech support is terrific. As far as beat up sidewalls. My 10.5wx31 M/T bias have 130 passes on them. 60fts on a preped track are within less than .01 if I don't experiment. If there was a 10.5x31 radial I'd run it. They won't allow us 315 radials
Doug