DOT (Department Of Transportation) Quality
Grades: All passenger car tires must conform
to federal safety requirements in addition to
these grades.TreadwearTreadwear 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 AA, A, B and CThe 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.
The traction grade assigned to your ve-
hicle tires is based on straight-ahead
braking traction tests, and does not in-
clude acceleration, cornering, hydro-
planing, or peak traction characteristics.Temperature A, B and CTemperature 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.
UNIFORM TIRE QUALITY
GRADING
Technical and consumer information
10-17
Z
01.1.31/A32-D
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