IMG - Photo by Jeannette Greenhaus

Car Classing

IMG uses a car classing system known as the Performance Index, which matches cars of similar capabilities and lap times together for close, competitive racing. If your car is already built for an existing racing or time trial class, use the class equivalency table below to quickly and easily identify your IMG performance index.

Custom Car Classification

Please fill out the form below as completely and accurately as possible. We will consider all of the details listed here and calculate your class based on what you input.

Contact Information

Your Name
Email Address
Phone Number

Base Vehicle Information

Make Model
Year Trim

Does your car fit into an existing racing or time trial class with another organization?
If so, which organization and class?

Wheel and Tire Information

Tire Type
Tire Size  /   / 
(e.g.: 225/50/15)


Displacement (in liters) L
# of Cylinders / Rotors
Compression (if known)  : 1

Please list all Engine Modifications:

Has the engine been swapped from what was originally sold with this vehicle?
If so, what type of engine is in the car now?


Please list all Modifications to the transmission, differentials, axles, and drivetrain:

Suspension & Brakes

Please list all Suspension and Brake System Modifications:

Chassis and Aerodynamics

Please list all Chassis Modifications, including wings and aerodynamic mods:


If you have any questions about classing your car, feel free to email us at