Where we have been testing the SJT rubber tires with a spec 17.5 (2.2kv) I am going to be testing them with a USGT spec 21.5 (1.9kv) motor this coming weekend. I have told the guys at the track that the current motor is fine but a little less power would probably be better for less skilled racers. It would also come closer to other area's rule sets. So far I have almost 20 runs on the tires with about .2mm of wear on the fronts. I can't determine if the rears have worn at all. One racer at our track (SG1 of TSR, and he is top level) has many more runs than I do. His comment is, I would have gone through 10+ sets of foams by now. I will let you know he only runs a set of foams about 2 to 3 runs because they are trued so small to start.
Just keeping you guys up to date on the testing.