FORD 2015 F-550 v.2 - Manual (Page 279)

Tire Wear
E142546
When the tread is worn down to
one sixteenth of an inch (2
millimeters), tires must be
replaced to help prevent your
vehicle from skidding and
hydroplaning. Built-in treadwear
indicators, or wear bars, which
look like narrow strips of smooth
rubber across the tread will
appear on the tire when the tread
is worn down to one sixteenth of
an inch (2 millimeters).
When the tire tread wears down
to the same height as these wear
bars, the tire is worn out and must
be replaced.
Damage
Periodically inspect the tire treads
and sidewalls for damage (such
as bulges in the tread or sidewalls,
cracks in the tread groove and
separation in the tread or
sidewall). If damage is observed
or suspected have the tire
inspected by a tire professional.
Tires can be damaged during
off-road use, so inspection after
off-road use is also
recommended.
Age
WARNING
Tires degrade over time
depending on many factors
such as weather, storage
conditions, and conditions of use
(load, speed, inflation pressure)
the tires experience throughout
their lives.
In general, tires should be
replaced after six years regardless
of tread wear. However, heat
caused by hot climates or
frequent high loading conditions
can accelerate the aging process
and may require tires to be
replaced more frequently.
You should replace your spare tire
when you replace the road tires or
after six years due to aging even if
it has not been used.
U.S. DOT Tire Identification
Number
Both United States and Canada
Federal regulations require tire
manufacturers to place
standardized information on the
sidewall of all tires. This
information identifies and
276
Super Duty (), enUSA
Wheels and Tires