Temperature Grades - Jeep Wrangler Owner's Manual

Temperature Grades

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 repre-
sent higher levels of performance on the laboratory test
wheel than the minimum required by law.
IF YOU NEED CONSUMER ASSISTANCE 427
WARNING!
The temperature grade for this tire is established for
a tire that is properly inflated and not overloaded.
Excessive speed, under inflation, or excessive load-
ing, either separately or in combination, can cause
heat buildup and possible tire failure.
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