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.

2022 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	0.830	SSP	0.853	XP	0.885	AM	1.000
AS	0.821	ASP	0.848	BP	0.867	BM	0.988
BS	0.818	BSP	0.852	CP	0.851	CM	0.895
CS	0.810	CSP	0.864	DP	0.865	DM	0.898
DS	0.806	DSP	0.844	EP	0.849	EM	0.909
ES	0.792	ESP	0.840	FP	0.874	FM	0.908
FS	0.805	FSP	0.824	HCR	0.814	FSAE	0.989.
GS	0.794
HS	0.786	SSR	0.842	SMF	0.845	KM	0.931
HCS	0.793			SM	0.861
		CAM-C	0.819	SSM	0.883
SSC	0.808	CAM-T	0.816
		CAM-S	0.839
STS	0.813
STX	0.817	XS-A	0.843
STR	0.828	XS-B	0.854
STU	0.829	EV	0.835
STH	0.812

Rick Ruth PAX/RTP Administrator

2022 Indexed Results	Champ Tour	Match Tour/CAM Challenge	Pro	Nationals
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