To help consumers evaluate their tires, the U.S. National Highway Traffic Safety Administration (NHTSA) created the Uniform Tire Quality Grading System (UTQG) . The UTQG rates tires are rated on their treadwear, traction performance, and temperature resistance. The grade for each of these can be found on the sidewall of your tire (except winter tires and certain light truck tires).

Treadwear

The UTQG treadwear grade indicates how long your tire tread will last in relation to other tires. For instance, a tire with a grade of 400 will last twice as long as a tire with a grade of 200, according to how it performed in the treadwear test.

Note: Actual tire performance can differ greatly for many reasons, including driving style, climate, tire inflation and vehicle weight.

Traction

The UTQG traction grade rates the ability of your tire to stop on wet pavement.
Traction performance is given one of the following grades, which you will find on the sidewall of your tire:
AA, A, B, C.
Tires with an AA grade stop faster on wet pavement than those with a C grade.

CAUTION: The UTQG traction tests do not test tires for cornering, acceleration, driving at high speed or driving on dry roads. Tires are tested with straight ahead braking only.

Temperature

The UTQG temperature grade indicates the ability of your tire to dissipate the heat generated by driving.
Over time, heat can cause damage to your tires.
Temperature resistance is given one of the following grades, which you will find on the sidewall of your tire:
A, B, C.
All tires sold in the United States must have at least a C rating.