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 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 measured
under controlled conditions on specified govern-
ment 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.
TEMPERATURE A, B AND C
The temperature grades A (the highest), B, and
C, representing the tire’s resistance to the gen-
eration of heat and its ability to dissipate heat
when tested under controlled conditions on a
specified indoor laboratory test wheel. Sustained
high temperature can cause the material of the
tire to degenerate and reduce tire life, and exces-
sive temperature can lead to sudden tire failure.
The grade C corresponds to a level of perfor-
mance which all passenger car tires must meet
under the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels
of performance on the laboratory test wheel than
the minimum required by law.
WARNING
The temperature grade for this tire is es-
tablished for a tire that is properly in-
flated and not overloaded. Excessive
speed, under-inflation, or excessive load-
ing, either separately or in combination,
can cause heat build-up and possible tire
failure.
UNIFORM TIRE QUALITY GRADING
9-14 Technical and consumer information
