Great tire. We typically run Nitto's, but the R1-S has changed that. I would like to try a set of the regular R1's, as these did cord at the sidewall very prematurely. We have emailed BFG regarding the cording. The R1-S's were used at High Plains Raceway on both a 1997 M3 sedan (ran a 1:57.1) and on a 1993 325is (powered by a 2.8L engine, prepped for NASA GTS3, ran a 2:03 down from 2:07 on nittos). I highly recommend these tires. Good life (we expect another 2-3 full days on the set even with the cording), can be run for 20-30 minute sessions at a time, and with spectacular grip. By far the best bang for your buck track tire wise. The track conditions at time of testing were 70F, sunny, calm wind.