DOT (Department of Transportation) Qual-
ity Grades: All passenger car tires must
conform to federal safety requirements in
addition to these grades.
Quality grades can be found where appli-
cable 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 rat-
ing based on the wear rate of the tire when
tested under controlled conditions on a
specified government test course. For ex-
ample, 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 low-
est, are AA, A, B, and C. Those grades repre-
sent the tire's ability to stop on wet pave-ment as measured under controlled
conditions on specified government test
surfaces of asphalt and concrete. A tire
marked C may have poor traction perfor-
mance.
