Society of Automotive Engineers (SAE) class of traction aid must be installed, based on the wheel clearance of the vehicle.
|SAE traction device class ||Minimum tread-face clearance ||Minimum side-wall clearance
The SAE Class "S" well clearance is a common requirement on newer cars, especially if after-market wider, low-profile, or larger tires and/or wheels are fitted.
The classes are defined as follows:
- SAE Class S - Regular (non-reinforced) passenger tire traction devices for vehicles with restricted wheel well clearance.
- SAE Class U - Regular (non-reinforced) and lug-reinforced passenger tire traction devices for vehicles with regular (non-restricted) wheel well clearances.
- SAE Class W - Passenger tire traction devices that use light truck components, as well as some light truck traction devices.