DOT (Department of Transportation) Quality
Grades: All passenger car tires must conform
to federal safety requirements in addition to
these grades.
Quality grades can be found where appli-
cable on the tire sidewall between tread
shoulder and maximum section width. For
example:
Treadwear 200 Traction AA Temperature A
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 ex-
ample, a tire graded 150 would wear one and
one-half (1 1/2) times as well on the govern-
ment course as a tire graded 100. The rela-
tive 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 prac-
tices and differences in road characteristics
and climate.
Traction AA, A, B and C
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 onspecified government test surfaces of as-
phalt 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 A, B and C
The temperature grades are A (the highest),
B, and C, representing the tire’s resistance to
the generation of heat, and its ability to dis-
sipate 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 tempera-
ture 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 temperature grade for this tire is es-
tablished for a tire that is properly inflated
and not overloaded. Excessive speed,
under-inflation, or excessive loading, either
separately or in combination, can cause
heat build-up and possible tire failure.
UNIFORM TIRE QUALITY GRADING
Technical and consumer information10-29
