DOT (Department of Transportation) Quality
Grades: All passenger car tires must conform
to Federal Safety Requirements in addition to
these grades.
Treadwear
Treadwear grade is a comparative rating
based on tire wear rate when tested under
controlled conditions on specified government
test courses. For example, 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. However, relative tire performance de-
pends on actual driving conditions, and may
vary significantly from the norm due to varia-
tions in driving habits, service practices and
differences in road characteristics and climate.
Traction A, B and C
Traction grades are A (the highest), B and C.
They represent a tire's ability to stop on wet
pavement as measured under controlled con-
ditions, on specified government test surfaces
of asphalt and concrete. A tire marked with a C
may have poor traction performance.
The traction grade assigned to your ve-
hicle tires is based on straight line brak-
ing traction tests and does not include
cornering (turning) traction.
Temperature A, B and C
Temperature grades are A (the highest), B,
and C. They represent a tire's resistance to
heat build-up, and its ability to dissipate heat
when tested under controlled conditions on a
specified indoor laboratory test wheel. Sus-
tained high temperature can cause tire mate-
rial to degenerate, reducing tire life. Excessive
temperatures can lead to sudden tire failure.
Grade C corresponds to a performance level
which all passenger car tires must meet under
the Federal Motor Vehicle Safety Standard No.
109. Grades A and B represent higher levels of
performance on laboratory test wheels than
the minimum required by law.
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 combina-
tion, can cause heat buildup and pos-
sible tire failure problems.
UNIFORM TIRE QUALITY
GRADING
9-17
Z01.2.1/A32-DX
