Treadwear; Temperature A, B, C; Traction Aa, A, B, C; Glossary Of Tire Terminology - Lexus LC500 Manual

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8-1. Specifications

Treadwear

■
The treadwear grade is a comparative
rating based on the wear rate of the
tire when tested under controlled con-
ditions 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.
Performance may differ significantly from
the norm due to variations in driving habits,
service practices and differences in road
characteristics and climate.

Traction AA, A, B, C

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The traction grades, from highest to
lowest, are AA, A, B and C, and they
represent the tire's ability to stop on
wet pavement as measured under con-
trolled conditions on specified govern-
ment 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

Glossary of tire terminology

Tire related term
Cold tire inflation
pressure
Maximum inflation
pressure
Recommended
inflation pressure
Tire pressure when the vehicle has been parked for three hours or
more, or has not been driven more than 1 mile or 1.5 km under that
condition
The maximum cold inflated pressure to which a tire may be inflated,
shown on the sidewall of the tire
Cold tire inflation pressure recommended by a manufacturer
ahead) traction tests and does not 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 condi-
tions 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.
Grade C corresponds to a level of perfor-
mance 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 grades of a tire
assume that it is properly inflated and not
overloaded.
Excessive speed, underinflation, or exces-
sive loading, either separately or in combi-
nation, can cause heat buildup and
possible tire failure.
Meaning