Temperature A B C; Checking The Tire Pressure; Tire Rotation - Mercury 1999 Mountaineer Owner's Manual

Maintenance and care

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 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 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,
underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
SERVICING YOUR TIRES

Checking the tire pressure

Use an accurate tire pressure gauge.
Check the tire pressure when tires are cold, after the vehicle has been
parked for at least one hour or has been driven less than 5 km (3
miles).
Adjust tire pressure to recommended specifications found on the
Safety Compliance Certification Label, located on the drivers door
jamb.
Improperly inflated tires can affect vehicle handling and can fail
suddenly, possibly resulting in loss of vehicle control.

Tire rotation

Because your vehicle's tires perform different jobs, they often wear
differently. To make sure your tires wear evenly and last longer, rotate
them as indicated in the Schedule maintenance guide. If you notice that
the tires wear unevenly, have them checked.
210