DOT (Department Of Transportation)
Quality Grades: All passenger car tires
must conform to federal safety require-
ments in addition to these grades.
Quality grades can be found where ap-
plicable on the tire sidewall between
tread shoulder and maximum section
width. For example:
Treadwear 200 Traction AA Tempera-
ture 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 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 ac-
tual conditions of their use, however, and
may depart significantly from the norm
due to variations in driving habits, service
practices and differences in road charac-
teristics and climate.
TRACTION AA, A, B AND C
The traction grades, from highest to low-
est, 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 perfor-
mance.
