I have been racing in Arizona for about a year now and the solaris 35's work great for me and i can usually get a good month to 2 months out of them. Track temps in the summer are high, i have seen it up to 130, during the midday during the summer. Others at the track like to use sorex as well. The muchmore's are a good tire if you want longevity, although you do loose some traction with that.