Uniform Tire Quality Grade
The Uniform Tire Quality Grade or UTQG rating is for passenger tires. This rating is a result of testing for relative treadwear, traction and temperature resistant capabilities. It is not required for light truck tires (non-passenger car), medium truck, winter/snow tires, temporary spare tires and trailer tires. In addition, this rating does not apply to tires under 12 inches in diameter and other select tires.
Nevertheless, UTQG grading is not precise. Manufacturers perform the tests or hire an independent testing company. Therefore, the grade may vary by manufacturer. The National Highway Traffic Safety Administration (NHTSA) does have the right to inspect the tire manufacturer’s data and can impose fines if the ratings are found to have inconsistencies.
UTQG Treadwear Grades
The Treadwear Grade rates how well a tire wears in comparison to a specific test tire. A tire with a grade of 300 wears three times as long as a tire with a grade of 100. While this test is a comparison, bear in mind that it is not how long a tire wears and results vary by manufacturer.
UTQG Traction Grades
The Traction Grade is the level of grip on a wet surface. Trailer-locking the brakes, skidding the tire while sensors measure the tires braking force or g-force are aspects of the testing to determine traction grade.
Traction Grades range for AA being the best rating to C being the worst rating.
UTQG Temperature Grades
The Temperature Grade measures how well a tire stands up to heat buildup and failure at high speeds.
Temperature Grades range for A (best rating) to C (worst rating).