The 2013 SCCA Solo Autocross PAX indexes have been released. The PAX index is used as a basis to compare times against cars across different classes. The PAX index is calculated based off of results from over 500 events nationwide.

Stock Classes
SS 0.859
AS 0.847
BS 0.845
CS 0.834
DS 0.826
ES 0.828
FS 0.830
GS 0.816
HS 0.804
Street Prepared
SSP 0.871
ASP 0.866
BSP 0.858
CSP 0.861
DSP 0.855
ESP 0.849
FSP 0.838
Street Touring & Modified
STF 0.795
STC 0.824
STS 0.829
STR 0.839
STX 0.827
STU 0.846

SM 0.867
SMF 0.852
SSM 0.881

Prepared
XP 0.901
BP 0.878
CP 0.862
DP 0.874
EP 0.875
FP 0.877
GP 0.850
Modified
AM 1.000
BM 0.962
CM 0.910
DM 0.918
EM 0.928
FM 0.917
Formula
FSAE 0.989
KM 0.955
JA 0.879
JB 0.842
JC 0.743

For historical PAX values visit Rick Ruth’s PAX/RTP page