FORD 2010 F-550 v.1 - Manual (Page 221)

WARNING: Under-inflation is the most common cause of tire
failures and may result in severe tire cracking, tread separation
or
ЉblowoutЉ, 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.
Note: Do not reduce tire pressure to change the ride characteristics of
the vehicle. If you do not maintain the inflation pressure at the levels
specified by Ford, your vehicle may experience a condition known as
ЉshimmyЉ. Shimmy is a severe vibration and oscillation in the steering
wheel after the vehicle travels over a bump or dip in the road that does
not dampen out by itself. Shimmy may result from significant
under-inflation of the tires, improper tires (load range, size, or type), or
vehicle modifications such as lift-kits. In the event that your vehicle
experiences shimmy, you should slowly reduce speed by either lifting off
the accelerator pedal or lightly applying the brakes. The shimmy will
cease as the vehicle speed decreases.
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.
Tires, Wheels and Loading
221
2010 F-250/350/450/550 (f23)
Owners Guide, 1st Printing
USA (fus)