Fiat 500 2017 User Manual page 159

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.
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 sud-
den tire failure. The grade C corresponds to a level of performance, which
all passenger vehicle 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.
The temperature grade for this tire is established for a tire that is properly
inflated and not overloaded. Excessive speed, under-inflation, or excessive
loading, either separately or in combination, can cause heat buildup and
possible tire failure.
MAINTAINING YOUR VEHICLE
WARNING!
WARNING!
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