9-18Technical and consumer information
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 applic-
able 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 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 actual conditions of their use, how-
ever, 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
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.
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 generation of heat and its ability to
dissipate heat when tested under con-
trolled 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
excessive temperature can lead to sudden tire failure. The grade C corresponds to a
level of performance 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
established for a tire that is properly
inflated and not overloaded. Excessive
speed, under-inflation, or excessive loading,
either separately or in combination, can
cause heat build-up and possible tire failure.
UNIFORM TIRE QUALITY GRADING
