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Uniform
Tire
Quality
Grading
The following information relates to the system developed by the United
States National Highway Traffic Safety Administration which grades tires
by treadwear, traction and temperature performance. (This applies only to
vehicles sold in the United States.)
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
112)
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 not include cornering (turning)
traction.
Temperature
-
A,
9,
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
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