Maintenance
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7. Uniform tire quality grading
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
Tread wear
The tread wear 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-a-half times (1½) as well
on the government course as a tire grad-
ed 100.
The relative performance of tires
depends upon the actual conditions of
their use, however, and may depart sig-
nificantly from the norm due to variations
in driving habits, service practices and
differences in road characteristics and
climate.
These grades are molded on the side-
walls of passenger vehicle tires. The tires
available as standard or optional equip-
ment on your vehicle may vary with
respect to grade.
Traction - AA, A, B & 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 per-
formance.
Temperature -A, B & C
The temperature grades are A (the high-
est), B, and C, representing the tire’s
resistance to the generation of heat and
its ability to dissipate heat when tested
under controlled conditions on a speci-
fied indoor laboratory test wheel.
Sustained high temperature can cause
the material of the tire to degenerate and
reduce tire life, and excessive tempera-
ture can lead to sudden tire failure.
Grades B and A represent higher levels
of performance on the laboratory test
wheel than the minimum required by law.
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.
WARNING - Tire tempera-
ture
The temperature grade for this tire
is established for a tire that is prop-
erly inflated and not overloaded.
Excessive speed, underinflation, or
excessive loading, either separate-
ly or in combination, can cause
heat build-up and possible sudden
tire failure. This can cause loss of
vehicle control and serious injury
or death.
