Lexus GS 450h 2008 Owner's Manual page 564

6-1. Specifications
■
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 fail-
ure.
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 represent higher levels of performance on the laboratory
test wheel than the minimum required by law.
Warning: The temperature grades for this tire are established for a tire that
is properly inflated and not overloaded.
Excessive speed, underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
Glossary of tire terminology
Tire related term
Cold tire inflation pres-
sure
Maximum inflation pres-
sure
Recommended inflation
pressure
562
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 man-
ufacturer
Meaning