2013 GMC SIERRA Owner's Manual

Black plate (47,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Vehicle Care 10-47
WARNING (Continued)
.Worn or old tires can
cause a crash. If the tread
is badly worn,
replace them.
.Replace any tires that
have been damaged by
impacts with potholes,
curbs, etc.
.Improperly repaired tires
can cause a crash. Only
the dealer or an
authorized tire service
center should repair,
replace, dismount, and
mount the tires.
.Do not spin the tires in
excess of 56 km/h
(35 mph) on slippery
surfaces such as snow,
mud, ice, etc. Excessive
spinning may cause the
tires to explode.See
Tire Pressure for
High-Speed Operation on
page 10‑56 for inflation pressure
adjustment for high speed
driving.
20‐Inch Tires
If the vehicle has 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 9‑5
and Adding a Snow Plow or
Similar Equipment on
page 9‑101 for additional
information.
Notice: Low‐profile tires 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 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.
All-Season Tires
This vehicle may come with
all-season tires. These tires are
designed to provide good overall
performance on most road surfaces
and weather conditions. Original
equipment tires designed to GM's
specific tire performance criteria
have a TPC specification code
molded onto the sidewall. Original
equipment all-season tires can be
identified by the last two characters
of this TPC code, which will
be
“MS.”

Black plate (48,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-48 Vehicle Care
Consider installing winter tires on
the vehicle if frequent driving on
snow or ice-covered roads is
expected. All-season tires provide
adequate performance for most
winter driving conditions, but they
may not offer the same level of
traction or performance as winter
tires on snow or ice-covered roads.
SeeWinter Tires on page 10‑48.
Winter Tires
This vehicle was not, originally,
equipped with winter tires. Winter
tires are designed for increased
traction on snow and ice-covered
roads. Consider installing winter
tires on the vehicle if frequent
driving on snow or ice-covered
roads is expected. See your dealer
for details regarding winter tire
availability and proper tire selection.
Also, see Buying New Tires on
page 10‑65. With winter tires, there may be
decreased dry road traction,
increased road noise, and shorter
tread life. After changing to winter
tires, be alert for changes in vehicle
handling and braking.
If using winter tires:
.Use tires of the same brand and
tread type on all four wheel
positions.
.Use only radial ply tires of the
same size, load range, and
speed rating as the original
equipment tires.
Winter tires with the same speed
rating as the original equipment tires
may not be available for H, V, W, Y,
and ZR speed rated tires. If winter
tires with a lower speed rating are
chosen, never exceed the tire's
maximum speed capability.
Summer Tires
This vehicle may come with high
performance summer tires. These
tires have a special tread and
compound that are optimized for
maximum dry and wet road
performance. This special tread and
compound will decrease
performance in cold climates, and
on ice and snow. We recommend
installing winter tires on the vehicle
if frequent driving in cold
temperatures or on snow or ice
covered roads is expected. See
Winter Tires on page 10‑48.
Tire Sidewall Labeling
Useful information about a tire is
molded into the sidewall. The
examples show a typical
passenger and light truck tire
sidewall.

Black plate (49,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Vehicle Care 10-49
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.
(B) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
(C) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that the
tire is in compliance with the
U.S. Department of
Transportation Motor Vehicle
Safety Standards.
DOT Tire Date of
Manufacture
:The last four
digits of the TIN indicate the tire
manufactured date. The first two
digits represent the week
(01-52) and the last two digits,
the year. For example, the third
week of the year 2010 would
have a four-digit DOT date
of 0310. (D) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT code are the
Tire Identification Number (TIN).
The TIN shows the
manufacturer and plant code,
tire size, and date the tire was
manufactured. The TIN is
molded onto both sides of the
tire, although only one side may
have the date of manufacture.
(E) Tire Ply Material
:The type
of cord and number of plies in
the sidewall and under the tread.
(F) Uniform Tire Quality
Grading (UTQG)
:Tire
manufacturers are required to
grade tires based on three
performance factors: treadwear,
traction, and temperature
resistance. For more
information, see Uniform Tire
Quality Grading on page 10‑67.

Black plate (50,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-50 Vehicle Care
(G) Maximum Cold Inflation
Load Limit
:Maximum load that
can be carried and the
maximum pressure needed to
support that load. For
information on recommended
tire pressure see Tire Pressure
on page 10‑55 andVehicle Load
Limits on page 9‑15.
Light Truck (LT-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.
(B) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
(C) Dual Tire Maximum Load
:
Maximum load that can be
carried and the maximum
pressure needed to support that
load when used in a dual
configuration. For information on
recommended tire pressure see
Tire Pressure on page 10‑55
and Vehicle Load Limits on
page 9‑15. (D) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that the
tire is in compliance with the
U.S. Department of
Transportation Motor Vehicle
Safety Standards.
DOT Tire Date of
Manufacture
:The last four
digits of the TIN indicate the tire
manufactured date. The first two
digits represent the week
(01-52) and the last two digits,
the year. For example, the third
week of the year 2010 would
have a four-digit DOT date
of 0310.
(E) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT code are the
Tire Identification Number (TIN).
The TIN shows the
manufacturer and plant code,
tire size, and date the tire was

Black plate (51,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Vehicle Care 10-51
manufactured. The TIN is
molded onto both sides of the
tire, although only one side may
have the date of manufacture.
(F) Tire Ply Material
:The type
of cord and number of plies in
the sidewall and under the tread.
(G) Single Tire Maximum
Load
:Maximum load that can
be carried and the maximum
pressure needed to support that
load when used as a single. For
information on recommended
tire pressure see Tire Pressure
on page 10‑55 andVehicle Load
Limits on page 9‑15.
Tire Designations
Tire Size
The examples show a typical
passenger vehicle and light
truck 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.

Black plate (52,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-52 Vehicle Care
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 mean
a light truck 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 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 kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
: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.

Black plate (53,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Vehicle Care 10-53
Belt:A rubber coated layer of
cords 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.
Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in kPa (kilopascal)
or psi (pounds per square inch)
before a tire has built up heat
from driving. See Tire Pressure
on page 10‑55.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the maximum capacity of fuel, oil,
and coolant, but without
passengers and cargo.
DOT Markings
:A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.
Department of Transportation
(DOT) Motor Vehicle Safety
Standards. The DOT code
includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight
Rating. See Vehicle Load Limits
on page 9‑15.
GAWR FRT
:Gross Axle Weight
Rating for the front axle. See
Vehicle Load Limits on
page 9‑15. GAWR RR
:Gross Axle Weight
Rating for the rear axle. See
Vehicle Load Limits on
page 9‑15.
Intended Outboard Sidewall
:
The side of an asymmetrical tire,
that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric
unit for air pressure.
Light Truck (LT-Metric) Tire
:A
tire used on light duty trucks and
some multipurpose passenger
vehicles.
Load Index
:An assigned
number ranging from 1 to 279
that corresponds to the load
carrying capacity of a tire.
Maximum Inflation Pressure
:
The maximum air pressure to
which a cold tire can be inflated.
The maximum air pressure is
molded onto the sidewall.

Black plate (54,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-54 Vehicle Care
Maximum Load Rating:The
load rating for a tire at the
maximum permissible inflation
pressure for that tire.
Maximum Loaded Vehicle
Weight
:The sum of curb
weight, accessory weight,
vehicle capacity weight, and
production options weight.
Normal Occupant Weight
:The
number of occupants a vehicle
is designed to seat multiplied by
68 kg (150 lbs). See Vehicle
Load Limits on page 9‑15.
Occupant Distribution
:
Designated seating positions.
Outward Facing Sidewall
:The
side of an asymmetrical tire that
has a particular side that faces
outward when mounted on a
vehicle. The side of the tire that
contains a whitewall, bears
white lettering, or bears
manufacturer, brand, and/or model name molding that is
higher or deeper than the same
moldings on the other sidewall
of the tire.
Passenger (P-Metric) Tire
:A
tire used on passenger cars and
some light duty trucks and
multipurpose vehicles.
Recommended Inflation
Pressure
:Vehicle
manufacturer's recommended
tire inflation pressure as shown
on the tire placard. See Tire
Pressure on page 10‑55 and
Vehicle Load Limits on
page 9‑15.
Radial Ply Tire
:A pneumatic
tire in which the ply cords that
extend to the beads are laid at
90 degrees to the centerline of
the tread.
Rim
:A metal support for a tire
and upon which the tire beads
are seated. Sidewall
:The portion of a tire
between the tread and the bead.
Speed Rating
:An
alphanumeric code assigned to
a tire indicating the maximum
speed at which a tire can
operate.
Traction
:The friction between
the tire and the road surface.
The amount of grip provided.
Tread
:The portion of a tire that
comes into contact with
the road.
Treadwear Indicators
:Narrow
bands, sometimes called wear
bars, that show across the tread
of a tire when only 1.6 mm (1/
16 in) of tread remains. See
When It Is Time for New Tires
on page 10‑64.
UTQGS (Uniform Tire Quality
Grading Standards)
:A tire
information system that provides
consumers with ratings for a