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 applicable 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 gov-
ernment test course. For example, a tire graded
150 would wear one and one-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 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 mea-
sured under controlled conditions on specified
government test surfaces of asphalt and con-
crete. A tire marked C may have poor traction
performance.
