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DEPARTMENT OF TRANSPORTATION UNIFORM TIRE
QUALITY GRADES
The following tire grading categories were established by the Na tional High-
way Traffic Safety Administration. The specific grade rating assigned by the
tire's manufacturer in each category is shown on the sidewall of the tires on
your vehicle.
All passenger vehicle tires mus t conform to Federal safety requirements in
addition to these grades.
Treadwear
The Treadwear grade is a comparative rating, based on the wear ra te of the
tire when tested under controlled conditions on a specified government test
course. For example, a tire graded 150 would wear one and one-half times
as well on the government course as a tire graded 100. The relative perfor-
mance of tires depends upon the actual conditions of their use, however,
and may depart significantly from the norm due to variations in driving hab-
its, service practices, and differences in road characteristics and climate.
Traction Grades
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 straight-ahead braking
traction tests, and does not include acceleration, cornering, hydroplaning, or
peak traction characteristics.
Temperature Grades
The temperature grades are A (the highest), B, and C, representing 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 temperature can lead to sud-
den tire failure. The grade C corresponds to a level of performance, which
MAINTAINING YOUR VEHICLE
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