Pax Index

Mobile Pax Calculater

Written By Tony “Mario” Crea

PAX could best be described as a relative index of performance in autocrossing, much the same way a handicap rating is given in the game of golf. PAX indexes are based on results from the SCCA National Championships (the best of the best) each September. How strongly a class performs compared to the thirty-something other classes represented helps determine PAX indexes the next year. The following is an example showing how PAX is used at events…
The class “A Modified” is the fastest class in autocrossing; it is expected that the cars in this class represent the pinnacle of autocross-specific race car design, engineering, and performance. The class rarely disappoints! Due to its unbelievable performance, the PAX index for this class is 1.000 (no handicap is given). This means that if an A Mod car runs a time of 50 seconds, it will show up on the final results as 50 seconds.
Now let’s compare this to a car in “C Street Prepared”, which has a PAX index of .844. A car in CSP runs a time of 62 seconds on the same course as the A Mod car, yet its time will appear as 52.328 on the final standings. This was done by multiplying the raw time by the PAX index. As a result, the CSP car finishes only 2.328 seconds (not 12 seconds) behind the A Mod car. Yes, it still lost based on raw speed alone, but it allowed the driver in the CSP car to finish much higher overall. Thus, most regions base their overall driver championship on PAX performance whereas class championships are based on raw times.

2021 PAX/RTP Index

Racers Theoretical Performance”

This Index was developed by Rick Ruth and reflects study of results from well over 500 nationwide Solo events including, the Tire Rack® Solo National Championships, National Tour, Alabama Region, Arkansas Region, Atlanta Region, Chicago Region, California Sports Car Club, Central Florida Region, Equipe Rapide (Florida & Texas), Great Lakes Solo Series, Hawaii Region, Houston Region, Midwest Divisional Series, Milwaukee Region, New England Region, Northwest Region, Northern New Jersey Region, Oregon Region, Philadelphia Region, Rocky Mountain Series, San Francisco Region, San Diego Region, South Jersey Region, St. Louis Region, Tri-State Sports Car Council, Texas Region, Washington DC Region, and many, many others.

SS 0.823 SSP 0.853 XP 0.882 AM 1.000
AS 0.821 ASP 0.849 BP 0.867 BM 0.962
BS 0.814 BSP 0.852 CP 0.851 CM 0.893
CS 0.809 CSP 0.865 DP 0.866 DM 0.895
DS 0.807 DSP 0.842 EP 0.850 EM 0.898
ES 0.793 ESP 0.839 FP 0.871 FM 0.911
FS 0.806 FSP 0.825 HCR 0.815 FSAE 0.963
GS 0.794
HS 0.782 SSR 0.843 SMF 0.841 KM 0.930
HCS 0.795 SM 0.854 JA 0.855
CAM-C 0.818 SSM 0.875 JB 0.820
SSC 0.812 CAM-T 0.817 JC 0.718
CAM-S 0.835
STS 0.811
STX 0.816  XS-A 0.838
STR 0.827  XS-B 0.856
STU 0.828  EV 0.826
STH 0.813

Rick Ruth PAX/RTP Administrator

2021 Indexed Results Champ Tour Match Tour/CAM Challenge Pro Nationals
2020 Indexed Results Champ Tour Match Tour/CAM Challenge Pro Nationals
2019 Indexed Results Champ Tour Match Tour/CAM Challenge Pro Nationals
2018 Indexed Results Champ Tour Match Tour/CAM Challenge Pro Nationals
2017 Indexed Results Champ Tour Match Tour Pro Nationals
2016 Indexed Results Champ Tour Match Tour Pro Nationals

Index archives
PAX/RTP 2019,2018, 2017, 2016, 20152014201320122011201020092008200720062005200420032002
PAX 20012000199919981997199619951994
RTP 2001200019991998199719961995

Past Nationals results
PAX/RTP 20152014201320122011201020092008200720062005200420032002
PAX 2001200019991998199719961995
RTP 2001200019991998199719961995

Past National Tour results
2015 DixieSan DiegoCollege StationCrows LandingBowling Green(M)LincolnMoultrie(M)DevensPikes PeakUtah(M)PackwoodToledo(M)Peru Cam Challenge(M), Wilmington
2014 DixieTexasSan DiegoWilmingtonNew JerseyAtlantaLincolnDevensCrows LandingRocky MountainPeruPackwoodWilmington
2013 DixieSunBeltSan DiegoDoverLincolnPeruRocky MountainBlythevillePackwoodMilwaukeeAyersWilmingtonSt. George
2012 DixieTexasSan DiegoLincolnBlythevilleNortheastPackwoodColoradoPeruBlytheville(2), St. Louis
2011 DixieHoustonSan DiegoAtlantaLincolnDelawareBlythevilleToledoPackwoodColoradoBlytheville(2)Nashville
2010 DixieTexasSan DiegoWendoverBlythevillePeruFinger LakesPackwoodBlytheville(2)
2009 DixieSan DiegoHoustonFarmingtonBlythevilleFinger LakesPeruPackwoodVailBlytheville(2)
2008 DixieSan DiegoFt. WorthAtlantaDevensPeruMilwaukeePackwoodKansas City
2007 DixieSan DiegoAtwaterWalnut RidgeHoustonHuntsvillePeruMilwaukeePackwood
2006 Ft. MyersSan DiegoWalnut RidgeHoustonAtwaterPeruDevensMilwaukeeDenverPackwood
2005 El PasoSan DiegoHoustonWalnut RidgeAtlantaAtwaterToledoPeruDevensPackwoodDenver
2004 ToledoPeruBremerton

ProSolo Index

The PAX/RTP Autocross Index page is hosted by Solo Performance Specialites, LLC.(SoloPerformance)    Visit SPS at

Past ProSolo results
2015 El ToroCrows LandingBlythevilleNew JerseyLincolnWilmington(May)Mineral WellsToledoPackwoodWilmington(Summer)Pro Finale
2014 BlythevilleEl ToroWashington DCMineral WellsLincolnCrows LandingToledoPackwoodWilmingtonPro Finale
2013 El ToroMineral WellsNew JerseyLincolnWashington DCFarmingtonBlythevillePackwoodToledoPro Finale
2012 MarylandTexasEl ToroLincolnBlythevillePackwoodFarmingtonToledoPro Finale
2011 Mineral WellsEl ToroBlythevilleNew JerseyLincolnOscodaColoradoPackwood