DOT Tire Quality Grading (U.S. Vehicles)
Uniform Tire Quality Grading
Quality grades can be found where
applicable on the tire sidewall
between the tread shoulder and the
maximum section width.
For example:
Treadwear 200
Traction AA
Temperature A
DOT Quality Grades
All passenger car tires must conform
to Federal Safety Requirements in
addition to these grades.
Treadwear
The treadwear grade is a compara-
tive 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 would wear one and one-
half (11/2) times as well on the
government course as a tire graded
100. The relative performance of
tires depends upon the actual condi-
tions 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 — AA, A, B, 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 on
specified government test surfaces
of asphalt 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.
Technical Information
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