I agree that the Pro Solo RTP/PAX is much less, if at all, biased against the street tire classes. In fact, I recommended that we use it instead of the Ruth index early in 2014 for that very reason. There is very little difference between the indices for R-comp classes between the Ruth index and the Pro Solo index, but Street Touring and Street classes are much lower in the Pro Solo index.jcox07 wrote:I was at nationals and didn't see a single r comp tire in the same class as street tires. DeWitt you are forgetting that at nationals you only run against cars in your class and not other classes. Yeah if you pax that the r comps did better, but at the pros where in the super challenge you run against other class cars in other classes the pax is adjusted and your dial in is set by the class winner. As in sts, the pax goes from .829 to .811 at pros and like my earlier post stated in 10 pro solos this year street tires won 5 and you can't ask for more than that if you are SCCA.
Class 2014 2015 2014 Pro
SS 0.843 0.835 0.822
AS 0.833 0.829 0.81
BS 0.831 0.826 0.808
CS 0.821 0.814 0.797
DS 0.815 0.812 0.803
ES 0.814 0.808 0.793
FS 0.818 0.810 0.795
GS 0.806 0.806 0.771
HS 0.797 0.796 0.766
STF 0.801 0.801 0.787
STS 0.829 0.828 0.811
STR 0.838 0.838 0.818
STX 0.827 0.831 0.806
STU 0.846 0.844 0.831
The Ruth 2015 index didn't even move half the difference between 2014 and 2014 Pro. Street Touring hardly changed at all.