Ford 2009 Mustang Owner's Manual page 151

WARNING: Under-inflation is the most common cause of tire
failures and may result in severe tire cracking, tread separation
or blowout , with unexpected loss of vehicle control and increased risk
of injury. Under-inflation increases sidewall flexing and rolling
resistance, resulting in heat buildup and internal damage to the tire. It
also may result in unnecessary tire stress, irregular wear, loss of
vehicle control and accidents. A tire can lose up to half of its air
pressure and not appear to be flat!
Always inflate your tires to the Ford recommended inflation pressure
even if it is less than the maximum inflation pressure information found
on the tire. The Ford recommended tire inflation pressure is found on
the Safety Compliance Certification Label or Tire Label which is located
on the B-Pillar or the edge of the driver's door. Failure to follow the tire
pressure recommendations can cause uneven treadwear patterns and
adversely affect the way your vehicle handles.
Maximum Permissible Inflation Pressure is the tire manufacturer's
maximum permissible pressure and/or the pressure at which the
maximum load can be carried by the tire. This pressure is normally
higher than the manufacturer's recommended cold inflation pressure
which can be found on the Safety Compliance Certification Label or Tire
Label which is located on the B-Pillar or the edge of the driver's door.
The cold inflation pressure should never be set lower than the
recommended pressure on the Safety Compliance Certification Label or
Tire Label.
When weather temperature changes occur, tire inflation pressures also
change. A 10°F (6°C) temperature drop can cause a corresponding drop
of 1 psi (7 kPa) in inflation pressure. Check your tire pressures
frequently and adjust them to the proper pressure which can be found
on the Safety Compliance Certification Label or Tire Label.
To check the pressure in your tire(s):
1. Make sure the tires are cool, meaning they are not hot from driving
even a mile.
If you are checking tire pressure when the tire is hot, (i.e. driven more
than 1 mile [1.6 km]), never "bleed" or reduce air pressure. The tires are
hot from driving and it is normal for pressures to increase above
recommended cold pressures. A hot tire at or below recommended cold
inflation pressure could be significantly under-inflated.
2009 05+ Mustang (197)
Owners Guide
USA (fus)
Tires, Wheels and Loading
151