Treadwear
The treadwear grade is a comparative rating based on the
wear rate of the tire when tested under controlled con-
ditions on a specified government test course. For ex-
ample, a tire graded 150 would wear one and a 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 Grades
The traction grades, from highest to lowest, are A, B, and
C, and they 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 is based on braking (straight-
ahead) traction tests and does not include cornering
(turning) performance.
Temperature Grades
The temperature grades are A (highest), B, and C, repre-
senting 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 passen-
ger 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 temperature grade 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.
202 IF YOU NEED CONSUMER ASSISTANCE
