x
Traction: AA, A, B or C
x
Temperature: A, B or C
For example: Treadwear 200, Traction AA, Temperature A.
All passenger car tires must conform to Federal Safety Requirements in addition to these grades.
Treadwear
The treadwear 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 (Treadwear-value 150) would wear one-and-one-half (1 1/2) 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 due to variations in driving habits, service practices and differences
in road characteristics and climate.
Traction
The traction grades, from highest to lowest, are AA, A, B and C. Those 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
⇒
.
Temperature
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 sudden tire failure.
The grade C corresponds to a level of performance which all passenger car 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
⇒
.
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.
WARNING
The temperature grade for this tire is established for a tire that is properly inflated and not
overloaded. Excessive speed, underinflation or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
