2011 GMC SIERRA wheel size

Black plate (47,1)GMC Sierra Owner Manual - 2011
Seats and Restraints 3-47
In addition, the vehicle may have
a passenger sensing system
for the right front passenger's
position, which includes sensors
that are part of the passenger's
seat. The passenger sensing
system may not operate
properly if the original seat
trim is replaced with non-GM
covers, upholstery or trim,
or with GM covers, upholstery
or trim designed for a different
vehicle. Any object, such as
an aftermarket seat heater
or a comfort enhancing pad
or device, installed under or
on top of the seat fabric, could
also interfere with the operation
of the passenger sensing
system. This could either
prevent proper deployment
of the passenger airbag(s) or
prevent the passenger sensing
system from properly turning
off the passenger airbag(s).
SeePassenger Sensing
System on page 3‑40. If you have any questions
about this, you should contact
Customer Assistance before you
modify your vehicle. The phone
numbers and addresses for
Customer Assistance are in
Step Two of the Customer
Satisfaction Procedure in
this manual. See
Customer
Satisfaction Procedure (U.S.
and Canada) on page 13‑1
or Customer Satisfaction
Procedure (Mexico) on
page 13‑3.
If the vehicle has rollover
roof-rail airbags, see Different
Size Tires and Wheels on
page 10‑79 for additional
important information. Q: What if I added a snow plow?
Will it keep the airbags from
working properly?
A: We have designed our airbag
systems to work properly under
a wide range of conditions,
including snow plowing with
vehicles that have the optional
Snow Plow Prep Package
(RPO VYU). But do not change
or defeat the snow plow's
“tripping mechanism.” If you do,
it can damage your snow plow
and your vehicle, and it may
cause an airbag inflation.

Black plate (2,1)GMC Sierra Owner Manual - 2011
10-2 Vehicle Care
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-57
Tire Sidewall Labeling . . . . . . 10-58
Tire Designations . . . . . . . . . . . 10-61
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-62
Tire Pressure . . . . . . . . . . . . . . . 10-66
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . 10-67
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-68
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-69
Tire Inspection . . . . . . . . . . . . . . 10-73
Tire Rotation . . . . . . . . . . . . . . . 10-73
Dual Tire Rotation . . . . . . . . . . 10-75
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . 10-76
Buying New Tires . . . . . . . . . . . 10-77
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . 10-79 Uniform Tire Quality
Grading . . . . . . . . . . . . . . . . . . . 10-80
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . 10-81
Wheel Replacement . . . . . . . . 10-82
Tire Chains . . . . . . . . . . . . . . . . . 10-83
If a Tire Goes Flat . . . . . . . . . . 10-84
Tire Changing . . . . . . . . . . . . . . 10-86
Full-Size Spare Tire . . . . . . . . 10-97
Jump Starting
Jump Starting . . . . . . . . . . . . . . 10-98
Towing
Towing the Vehicle . . . . . . . . 10-103
Recreational Vehicle
Towing . . . . . . . . . . . . . . . . . . . 10-103
Appearance Care
Exterior Care . . . . . . . . . . . . . . 10-108
Interior Care . . . . . . . . . . . . . . . 10-112
Floor Mats . . . . . . . . . . . . . . . . . 10-116
General Information
For service and parts needs,
visit your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks:

Black plate (58,1)GMC Sierra Owner Manual - 2011
10-58 Vehicle Care
20‐Inch Tires
If your vehicle has the optional
20‐inch P275/55R20 size tires,
they are classified as touring
tires and are designed for
on road use. The low‐profile,
wide tread design is not
recommended for“off‐road”
driving or commercial uses
such as snow plowing. See
Off-Road Driving on page 9‑7
and Adding a Snow Plow
or Similar Equipment on
page 9‑125 for additional
information.
Notice: If the vehicle has
low‐profile tires, they are more
susceptible to damage from
road hazards or curb impact
than standard profile tires. Tire and/or wheel assembly
damage can occur when
coming into contact with
road hazards like, potholes,
or sharp edged objects,
or when sliding into a curb.
The vehicle warranty does
not cover this type of damage.
Keep tires set to the correct
inflation pressure and, when
possible avoid contact with
curbs, potholes, and other
road hazards.
Tire Sidewall Labeling
Useful information about a
tire is molded into the sidewall.
The following illustrations are
examples of a typical P‐Metric
and a LT‐Metric tire sidewall.
Passenger (P‐Metric) Tire
(A) Tire Size:The tire size
code is a combination of letters
and numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size” illustration later in this
section for more detail.

Black plate (61,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-61
Tire Designations
Tire Size
The following examples show
the different parts of a tire size.
Passenger (P‐Metric) Tire
(A) Passenger (P‐Metric) Tire:
The United States version of
a metric tire sizing system.
The letter P as the first
character in the tire size
means a passenger vehicle
tire engineered to standards
set by the U.S. Tire and Rim
Association.
(B) Tire Width
:The three‐digit
number indicates the tire section
width in millimeters from
sidewall to sidewall. (C) Aspect Ratio
:A two‐digit
number that indicates the tire
height‐to‐width measurements.
For example, if the tire size
aspect ratio is 75, as shown
in item C of the tire illustration,
it would mean that the tire's
sidewall is 75 percent as high
as it is wide.
(D) Construction Code
:A
letter code is used to indicate
the type of ply construction in
the tire. The letter R means
radial ply construction; the
letter D means diagonal or
bias ply construction; and the
letter B means belted‐bias ply
construction.
(E) Rim Diameter
:Diameter of
the wheel in inches. (F) Service Description
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire
is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Light Truck (LT‐Metric) Tire
(A) Light Truck (LT‐Metric)
Tire
:The United States version
of a metric tire sizing system.
The letters LT as the first two
characters in the tire size means
a light truck tire engineered to
standards set by the U.S. Tire
and Rim Association.

Black plate (62,1)GMC Sierra Owner Manual - 2011
10-62 Vehicle Care
(B) Tire Width:The three‐digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(C) Aspect Ratio
:A two‐digit
number that indicates the tire
height‐to‐width measurements.
For example, if the tire size
aspect ratio is 75, as shown
in item C of the light truck
(LT‐Metric) tire illustration,
it would mean that the tire's
sidewall is 75 percent as high
as it is wide.
(D) Construction Code
:A
letter code is used to indicate
the type of ply construction in
the tire. The letter R means
radial ply construction; the
letter D means diagonal or
bias ply construction; and the
letter B means belted‐bias ply
construction. (E) Rim Diameter
:Diameter of
the wheel in inches.
(F) Load Range
:Load Range.
(G) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage
(single/dual). The speed rating
is the maximum speed a tire is
certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount
of air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in psi (pounds per
square inch) or kPa (kilopascal). Accessory Weight
:This
means the combined weight
of optional accessories.
Some examples of optional
accessories are, automatic
transmission, power steering,
power brakes, power windows,
power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords that is located between
the plies and the tread. Cords
may be made from steel or
other reinforcing materials.
Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.

Black plate (73,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-73
Tire Inspection
We recommend that you
regularly inspect the vehicle's
tires, including the spare tire,
if the vehicle has one, for signs
of wear or damage at least once
a month.
Always remove the tires if any
of the following statements
are true:
.You can see the indicators at
three or more places around
the tire.
.You can see cord or fabric
showing through the tire's
rubber.
.The tread or sidewall is
cracked, cut, or snagged
deep enough to show cord
or fabric.
.The tire has a bump, bulge,
or split.
.The tire has a puncture, cut,
or other damage that cannot
be repaired well because of
the size or location of the
damage.
Tire Rotation
Tires should be rotated every
12 000 km (7,500 miles).
SeeScheduled Maintenance on
page 11‑2.
The purpose of a regular tire
rotation is to achieve a uniform
wear for all tires on the vehicle.
This will ensure that your vehicle
continues to perform most like it
did when the tires were new.
Any time you notice unusual
wear, rotate your tires as soon
as possible and check wheel
alignment. Also check for
damaged tires or wheels. See
When It Is Time for New
Tires on page 10‑76 andWheel
Replacement on page 10‑82.
If your vehicle has dual rear
wheels, also see Dual Tire
Rotation on page 10‑75.
If your vehicle has single rear
wheels and the tread design for
the front tires is the same as
the rear tires, use the rotation
pattern shown here when
rotating the tires.

Black plate (78,1)GMC Sierra Owner Manual - 2011
10-78 Vehicle Care
GM recommends replacing tires in
sets of four. This is because uniform
tread depth on all tires will help
keep the vehicle performing most
like it did when the tires were new.
Replacing less than a full set of
tires can affect the braking and
handling performance of the vehicle.
SeeTire Inspection on page 10‑73
and Tire Rotation on page 10‑73 for
information on proper tire rotation.
{WARNING
Tires could explode during
improper service. Attempting to
mount or dismount a tire could
cause injury or death. Only your
dealer or authorized tire service
center should mount or dismount
the tires.
{WARNING
Mixing tires could cause you
to lose control while driving.
If you mix tires of different sizes,
brands, or types (radial and
bias-belted tires), the vehicle
might not handle properly, and
you could have a crash. Using
tires of different sizes, brands,
or types could also cause
damage to the vehicle. Be sure
to use the same size, brand,
and type of tires on all wheels.
This vehicle may have a different
size spare than the road tires
(those originally installed on the
vehicle). When new, the vehicle
included a spare tire and wheel
assembly with a similar overall
diameter as the vehicle's road
tires and wheels, so it is all right
to drive on it. Because this spare
was developed for use on the
vehicle, it will not affect vehicle
handling.
{WARNING
Using bias-ply tires on the
vehicle may cause the wheel
rim flanges to develop cracks
after many miles of driving.
A tire and/or wheel could fail
suddenly and cause a crash.
Use only radial-ply tires with
the wheels on the vehicle.
If you must replace the vehicle's
tires with those that do not have
a TPC Spec number, make sure
they are the same size, load range,
speed rating, and construction type
(radial and bias‐belted tires) as the
vehicle's original tires.

Black plate (79,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-79
Vehicles that have a tire pressure
monitoring system may give an
inaccurate low‐pressure warning
if non‐TPC Spec-rated tires are
installed on the vehicle. Non‐TPC
Spec-rated tires may give a
low‐pressure warning that is
higher or lower than the proper
warning level you would get with
TPC Spec-rated tires. SeeTire
Pressure Monitor System on
page 10‑68.
The vehicle's original equipment
tires are listed on the Tire and
Loading Information label. See
Vehicle Load Limits on page 9‑25
for more information about the Tire
and Loading Information label and
its location on the vehicle.Different Size Tires and
Wheels
If you add wheels or tires that are
a different size than the original
equipment wheels and tires, this
could affect the way the vehicle
performs, including its braking,
ride and handling characteristics,
stability, and resistance to rollover.
Additionally, if the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, and electronic stability
control, the performance of these
systems can be affected.
{WARNING
If different sized wheels are used,
there may not be an acceptable
level of performance and safety
if tires not recommended for
those wheels are selected.
This increases the chance
of a crash and serious injury.
Only use GM specific wheel
and tire systems developed
for the vehicle, and have them
properly installed by a GM
certified technician.
See Buying New Tires on
page 10‑77 andAccessories
and Modifications on page 10‑3
for additional information.