I thought I would post what I'm seeing for Heat Cycle (HC) and tire longevity out of the different compounds and brands I have been trying out on California tracks. So far this year I have tried:
Goodyear bias ply slicks in R600 compound
Hoosier bias ply slicks in R45A compound
I'm running pretty big sizes on a 2400lbs car with 23.5x11.5x16 fronts and 25x13x16 rears, but the compounds are supposedly the same for the different tire sizes on the product lines. Tracks driven this year have been Thunderhill, Infineon, Buttonwillow and Laguna Seca.
I started on the Goodyear's with the R600 compound. This a harder compound than I have run in the past but is part of a mandated spec series I plan on running later this year or next year. Cold characteristics are that they need 2 full laps to heat up. What I found is that once heated they feel very similar to the R430 Goodyear compound. The R600's felt great through 16 HC's but what was even more impressive was that I was able to get 27 heat cycles out of them before they had a severe degradation in lap times (2.5 seconds at Thunderhill on a 3 mile config). I ran the tires another 10 heat cycles before they developed a dime sized cord patch on the right front. All told that is 37 HC's before cording and 27 HC's before significant lap time degradation.
I am currently testing the Hoosier R45A compound on my car now. In back to back tests lap times confirmed that my car is 2 seconds quicker per lap with this softer compound compared to the Goodyear R600's. This is not surprising in that the R600's are a much harder compound than the Hoosier R45A. However, Hoosier does not make my tire sizes in the R55 compound. I will be tracking the HC and handling of these tires and will update the Paddock when I have more data. I will then switch to the more traditional Goodyear R430 compound that is used most often. This should give us a little data on how the HC and tire wear characteristics compare with the different companies and compounds.
Bill P.