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 a 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 - A, B, C
The traction grades, from highest to
lowest are:
A, B, and C. They 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 performance.
Warning: The traction grade assigned
to
this tire is based on braking
(straight-ahead) traction tests and does
no1 include cornering (turning) traction.
Temperature - A, B, C
The temperature grades are 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
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 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
261
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