GMC 2011 Sierra Denali, Owner'S Manual, Page: 407 / 492

Vehicle Care 10-63
Lightly coat the center of the
wheel hub with wheel bearing
grease after a wheel change or
tire rotation to prevent corrosion
or rust build-up. Do not get
grease on the flat wheel
mounting surface or on the
wheel nuts or bolts.
When It Is Time for
New Tires
Various factors, such as
maintenance, temperatures, driving
speeds, vehicle loading, and road
conditions influence when you need
new tires.
One way to tell when it is time for
new tires is to check the treadwear
indicators, which appear when the
tires have only 1.6 mm (1/16 in) or
less of tread remaining. Some
commercial truck tires may not have
treadwear indicators. See
Tire
Inspection on page 10 ‑ 61 and Tire
Rotation on page 10 ‑ 62 for
additional information.
The rubber in tires ages over time.
This is also true for the spare tire,
if the vehicle has one, even if it is
not being used. Multiple conditions
affect how fast this aging takes
place, including temperatures,
loading conditions, and inflation
pressure maintenance. Tires will
typically need to be replaced due to
wear before they may need to be
replaced due to age. Consult the tire
manufacturer for more information
on when tires should be replaced.
Vehicle Storage
Tires age when stored normally
mounted on a parked vehicle.
Park a vehicle that will be stored for
at least a month in a cool, dry, clean
area away from direct sunlight to
slow aging. This area should be free
of grease, gasoline or other
substances that can deteriorate
rubber.
Parking for an extended period can
cause flat spots on the tires that
may result in vibrations while
driving. When storing a vehicle for
at least a month, remove the tires or
raise the vehicle to reduce the
weight from the tires.