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 (Treadwear-value 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 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
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 government test
surfaces of asphalt and concrete. A tire marked C may have poor
traction performance ⇒ꢀ
.
Temperature
The temperature grades are A (the highest), B, and C representing
the tire's resistance to the generation of heat, and its ability to dissi-
pate heat when tested under controlled conditions on a specified in-
door laboratory test wheel.
Sustained high temperature can cause the material of the tire to de-
generate and reduce tire life, and excessive temperature can lead to
sudden tire failure.
The grade C corresponds to a level of performance which all passen-
ger car tires must meet under the Federal Motor Vehicle Safety
Standard No. 109. Grades B and A represent higher levels of perfor-
mance 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.
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