Uniform Tire Quality Grading System (UTQGS); Customer Information and Reporting Safety Defects- Page 480

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Customer Information and Reporting Safety Defects

Uniform Tire Quality Grading System (UTQGS)

Uniform Tire Quality Grading System (UTQGS)

This information relates to the tire grading system developed by the U.S. National Highway 

Traffic Safety Administration for grading tires by tread wear, traction, and temperature 

performance.

 Tread Wear

The tread wear grade is a comparative rating based on the wear rate of the tire when tested 

under controlled conditions on a specified government test course.

For example, a tire graded 150 would wear one-and-a-half times as well on the government 

course as a tire graded 100.

The relative performance of tires depends upon the actual conditions of their use, however, 

and may depart significantly from the norm because of variations in driving habits, service 

practices and differences in road characteristics and climate.

 Traction-AA, A, B, C

The traction grades, from highest to lowest, are AA, A, B, and C. These grades represent the 

tire's ability to stop on wet pavement as measured under controlled conditions on specified 

government test surfaces of asphalt and concrete. A tire marked C may have poor traction 

performance.

WARNING

The traction grade assigned to this tire is based on braking (straight ahead) traction tests 

and does not include acceleration cornering (turning), hydroplaning, or peak traction 

characteristics.

 Temperature-A, B, C

The temperature grades A (the highest), B, and C, represent the tire's resistance to the 

generation of heat and its ability to dissipate heat when tested under controlled conditions on 

a specified indoor laboratory test wheel.

Sustained high temperature can cause the material of the tire to degenerate and reduce tire 

life, and excessive temperatures can lead to sudden tire failure.

Grade C corresponds to a level of performance which all passenger vehicle tires must meet 

under the Federal Motor Vehicle Safety Standard No. 109. Grades B and A represent higher 

levels of performance on the laboratory test wheel than the minimum required by law.

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