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