load capacity GMC SIERRA 2021 User Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 365
(1) 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.
(2) Tire Width
:The 3-digit number
indicates the tire section width in
millimeters from sidewall to sidewall.
(3) Aspect Ratio
:A 2-digit number that
indicates the tire height-to-width
measurements. For example, if the tire
size aspect ratio is 75, as shown in item
3 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.
(4) 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.
(5) Rim Diameter
:Diameter of the
wheel in inches. (6) Load Range
:Load Range.
(7) 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
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
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 Pressure0367.
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)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
366 Vehicle Care
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 0222.
GAWR FRT
:Gross Axle Weight Rating
for the front axle. See Vehicle Load
Limits 0222.
GAWR RR
:Gross Axle Weight Rating
for the rear axle. See Vehicle Load
Limits 0222.
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.
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 lb). See
Vehicle Load Limits 0222.
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 Pressure0367 and
Vehicle Load Limits 0222.
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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 367
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 0375.
UTQGS (Uniform Tire Quality Grading
Standards)
:A tire information system
that provides consumers with ratings
for a tire's traction, temperature, and
treadwear. Ratings are determined by
tire manufacturers using government
testing procedures. The ratings are
molded into the sidewall of the tire.
See Uniform Tire Quality Grading 0377.
Vehicle Capacity Weight
:The number
of designated seating positions
multiplied by 68 kg (150 lb) plus the
rated cargo load. See Vehicle Load
Limits 0222. Vehicle Maximum Load on the Tire
:
Load on an individual tire due to curb
weight, accessory weight, occupant
weight, and cargo weight.
Vehicle Placard
:A label permanently
attached to a vehicle showing the
vehicle capacity weight and the original
equipment tire size and recommended
inflation pressure. See “Tire and Loading
Information Label” underVehicle Load
Limits 0222.
Tire Pressure
Tires need the correct amount of air
pressure to operate effectively.
{Warning
Neither tire underinflation nor
overinflation is good. Underinflated
tires, or tires that do not have
enough air, can result in:
.Tire overloading and overheating,
which could lead to a blowout.
.Premature or irregular wear.
.Poor handling.
(Continued)
Warning (Continued)
.Reduced fuel economy.
Overinflated tires, or tires that have
too much air, can result in:
.Unusual wear.
.Poor handling.
.Rough ride.
.Needless damage from road
hazards.
The Tire and Loading Information label
on the vehicle indicates the original
equipment tires and the correct cold
tire inflation pressures. The
recommended pressure is the minimum
air pressure needed to support the
vehicle's maximum load carrying
capacity.
For additional information regarding
how much weight the vehicle can carry,
and an example of the Tire and Loading
Information label, see Vehicle Load
Limits 0222. How the vehicle is loaded
affects vehicle handling and ride

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 379
Your dealer will know the kind of wheel that
is needed.
Each new wheel should have the same
load-carrying capacity, diameter, width,
offset, and be mounted the same way as
the one it replaces.
Replace wheels, wheel bolts, wheel nuts,
or Tire Pressure Monitor System (TPMS)
sensors with new GM original equipment
parts.
{Warning
Using the wrong replacement wheels,
wheel bolts, or wheel nuts can be
dangerous. It could affect the braking and
handling of the vehicle. Tires can lose air,
and cause loss of control, causing a crash.
Always use the correct wheel, wheel
bolts, and wheel nuts for replacement.
Caution
The wrong wheel can also cause
problems with bearing life, brake cooling,
speedometer or odometer calibration,
headlamp aim, bumper height, vehicle
ground clearance, and tire or tire chain
clearance to the body and chassis.
Used Replacement Wheels
{Warning
Replacing a wheel with a used one is
dangerous. How it has been used or how
far it has been driven may be unknown.
It could fail suddenly and cause a crash.
When replacing wheels, use a new GM
original equipment wheel.
Tire Chains
{Warning
If the vehicle has 275/50R22, 275/60R20,
LT265/60R20, LT265/70R17, or LT275/65R18
size tires, do not use tire chains. There is
not enough clearance. Tire chains used on
a vehicle without the proper amount of
clearance can cause damage to the
brakes, suspension, or other vehicle parts.
The area damaged by the tire chains
could cause loss of control and a crash.
Use another type of traction device only
if its manufacturer recommends it for the
vehicle's tire size combination and road
conditions. Follow that manufacturer's(Continued)
Warning (Continued)
instructions. To avoid vehicle damage,
drive slow and readjust or remove the
traction device if it is contacting the
vehicle. Do not spin the wheels.
If traction devices are used, install them
on the rear tires.
Caution
If the vehicle is equipped with a tire size
other than 275/50R22, 275/60R20,
LT265/60R20, LT265/70R17, or LT275/65R18
use tire chains only where legal and only
when necessary. Use chains that are the
proper size for the tires. Install them on
the tires of the rear axle. Do not use
chains on the tires of the front axle.
Tighten them as tightly as possible with
the ends securely fastened. Drive slowly
and follow the chain manufacturer's
instructions. If the chains contact the
vehicle, stop and retighten them. If the
contact continues, slow down until it
stops. Driving too fast or spinning the
wheels with chains on will damage the
vehicle.