Autocross Car Class Index

This is the Trillium autocross car class index (with PAX factor values)

The BMWCC Trillium autocross scoring model is based on the SCCA SOLO II PAX/RTP "Racers Theoretical Performance" Index. The system is an attempt to neutralize the car factor; it emphasizes the driver and his or her ability, no matter the vehicle driven.

The PAX/RTP index reflects analysis of results from over 200 U.S. Solo II events including, the Solo II National Championships, National Tour, regional and division events, from 1995 to present. It is continuously monitored and updated on an annual (if not more frequent) basis.

A proficient driver in a Formula 1 car (class AM, factor 1.000) could turn a particular time of say 40 seconds. Then take about 52 seconds in his stock '93 BMW 318i (class HS, factor 0.780) daily driver. His factored time are computed as follows:

F1: 1.000 x 40s = 40.00s

318i: 0.780 x 52s = 40.56s

In other words, he turns about the same (factored) time, no matter which car he drives.


AS 0.831 new M Coupé & Roadster; E46 M3; Z4; etc.
BS 0.822 E30 M3; E36 M3; Z3 6cyl; etc.
CS 0.813 MR2 supercharged; new Miata 1.8
DS 0.798 330; 3 series, 6-cyl
ES 0.806 Z3, 4-cyl; Porsche 924 Turbo
FS 0.805 big bimmers; old M5s, etc.
GS 0.794 318is; 318ti ('95+); 325e; 2002; MINI Cooper S; etc.
HS 0.780 318; 320; 7 series; MINI Cooper; etc.

Note: The BMW M3 Lightweight, MINI Works (pre-06 dealer installed), BMW Z8, among others, are not eligible for stock class.

street prepared
ASP 0.852 M Coupé; Roadster; E46 M3; etc.
BSP 0.843 E36 M3; Z8; etc.
CSP 0.838 Z3 4-cyl; E30 M3; etc.
DSP 0.829 various 3 series; 318ti; etc.
ESP 0.828 5, 6, and 7 series; MINI Cooper S; etc.
FSP 0.814 2002; 320i; MINI Cooper; etc.


super stock
SS 0.840 Porsche 996 and 997; Viper; Elise; etc.


street modified
SM 0.842 4 doors
SM2 0.852 2 doors


street touring
STS 0.797
STS2 0.802
STX 0.804
STU 0.820


prepared (race)
XP 0.868 replaces AP
AP 0.865 discontinued
BP 0.862  
CP 0.856  
DP 0.853  
EP 0.858  
FP 0.863  
GP 0.844 new for 2006


Formula junior
F125 0.937
FJ1 0.781
FJ2 0.796
FJ3 (FJB) 0.830
FJ4 (FJA) 0.837


modified (race)
AM 1.000
BM 0.944
CM 0.909
DM 0.885
EM 0.881
FM 0.887
FSAE 0.948

See the

car classification worksheet

to determine final class of car given its preparation and modifications.