Originally Posted by SCCAForums.com
Fractionally? You should do some research on the Cup's that are unique to the Z06/ZR1 by Michelin... 1/32nd less tread than their standard Cups... less 'grooves' overall... much closer to a dedicated track tire now. You're correct on the original PS-Cups... but not the new round offered exclusively for the Vette.
A shaved tire is what all competitive competition auto crossers, including myself, do to their tires (R compound or not) before an event in order to get to the 'sweet' spot
Put RE11's, AD08's, Re070r, Pilot SS on a Z06/ZR1 (not the ancient Eagle F1 OE tire) then put on PS cups equipped on a GT3 or ZR1, which are the "n-spec" cup tire, not the race spec PSCup.
Shave either of them or leave them be and check your times and get back to me....
I've been around data logging this type of information since I was 14 years old.
A Ps-Cup "n-spec" is by no means a fast R comp (also equipped on M3 ZCP's), it falls more in line with a excellent summer tire in terms of what speeds/times it is capable of but they do put up with heat well. The plus side vs. other R comps, is they are street friendly, have a longer life and they are treaded. The downside, is they aren't that fast...
If your still trying to craft my point, it's that just because it says R compound does not mean it's instantly a x second advantage over a 180 tread wear summer tire. An Bridgestone RE11 (180 IIRC treadwear) is simply a faster tire then numerous R compounds available in these circumstances, but one just would not necessarily have the consistency if he were to run numerous laps, on a hot day with a professional driver.
However, you did bring up a good point that I did not know, and that's that the tire comes shaved from the factory just for magazine bragging #'s. That is just unfair as one would benefit significantly from shaving RS3's, RE11's, RE070r's etc. etc. as well