The Department of Transportation requires each manufacturer to grade its tires under the Uniform Tire Quality Grade (UTQG) labeling system and establish ratings for treadwear, traction, and temperature resistance. These tests are conducted independently by each manufacturer following government guidelines to assign values that represent a comparison between the tested tire and a control tire. While traction and temperature resistance ratings are specific performance levels, the treadwear ratings are assigned by the manufacturers following field-testing and are most accurate when comparing tires of the same brand.
Treadwear
Treadwear receives a comparative rating based on wear rate of the tire in field-testing following a government specified course. For example, a tire grade of 150 wears 1.5 times as long as a tire graded 100. Actual performance of the tire can vary significantly depending on conditions, driving habits, care, road characteristics, and climate.
Traction
Straight-a-head wet braking traction has been represented by a grade of A, B, or C with A being the highest. In 1997 a new top rating of "AA" has been introduced to indicate even greater wet braking traction. However, due to its newness, this grade will probably be applied initially to new tire lines as they are introduced and later to existing lines which excel in wet braking, but had been limited to the previous top grade of "A". Traction grades do not indicate wet cornering ability.
Temperature
Temperature resistance is graded A, B or C. It represents the tire's resistance to the heat generated by running at high speed. Grade C is the minimum level of performance for all passenger car tires as set under Federal Motor Vehicle Safety Standards. This grade is established for a tire that is properly inflated and not overloaded.
Note: UTQG ratings are not required on winter and light truck sized tires.
The most important thing to remember: Don't compare the UTQG rating of Brand A Tire B to Brand B Tire B. Unless you're comparing tires of the same brand, the numbers won't provide any insight into the pair's correlations or differences.
UTQG ratings are shown in all search results at The Tire Rack. Other research tools to help you select the best tires for your vehicle, your driving style and the conditions in which you drive are available there as well:
• Tire Test Results
• Consumer Reviews
• Survey Results
• Tech Articles
• Tire Decision Guide
Click here to check them out.