Ford 2003 Mustang Owner's Manual page 162

Maintenance and care
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 Certification Label.
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 Scheduled Maintenance Guide. If you notice
that the tires wear unevenly, have them checked.
162