Car Classes
We class cars with a simple system of model, year and modifications. When registering for an autocross, you will see a link where you can find your model, year, and indicate if it has modifications (see the list below). The car classes are:
Class A - “B” Class cars that are Modified
Class B - “B” Class cars and “C” Class cars that are Modified
Class C - “C” Class cars and “D” Class cars that are Modified
Class D - “D” Class cars and “E” Class cars that are Modified
Class E - “E” Class cars and “F” Class cars that are Modified
Class F - “F” Class cars
Class X - ALL non-BMWs and non-MINIs; BMWs with non-BMW engines
Class G - Gold Class for all Instructors
These are the ONLY modifications permitted to be considered a STOCK car:
- ANY size wheel and tires. Tires must have DOT treadwear rating of 140 or higher
- ANY shock absorber using stock mounting and ANY suspension bushing material
- ANY air filter or air intake AHEAD OF mass airflow meter
- Non-stock software/firmware is permitted on naturally-aspirated engines only
- ANY brake pad material is allowed with Stock-size brake components
- Catalyst-back exhaust systems and strut tower braces are permitted
ANY other modifications means your car is considered MODIFIED, which moves your car UP ONE CLASS, including:
- Tires with DOT treadwear rating under 140
- Non-stock springs, camber plates, coilover suspensions, non-stock anti-roll bars
- Software/firmware alterations to turbocharged/supercharged engines
- Non-stock mass airflow meters, camshafts, downpipes, removed catalytic converter
- Non-stock-size brake rotors or calipers (stock-size replacements OK in Stock)