Black plate (22,1)Chevrolet Silverado Owner Manual - 2012
9-22 Driving and Operating
Using heavier suspension
components to get added
durability might not change your
weight ratings. Ask your dealer
to help you load your vehicle the
right way.
If you put things inside your
vehicle—like suitcases,
tools, packages, or anything
else —they go as fast as the
vehicle goes. If you have to stop
or turn quickly, or if there is a
crash, they will keep going.
{WARNING
Things you put inside the
vehicle can strike and injure
people in a sudden stop or
turn, or in a crash.
.Put things in the cargo
area of the vehicle.
Try to spread the weight
evenly.
(Continued)
WARNING (Continued)
.Never stack heavier
things, like suitcases,
inside the vehicle so that
some of them are above
the tops of the seats.
.Do not leave an
unsecured child restraint
in the vehicle.
.When you carry something
inside the vehicle, secure
it whenever you can.
.Do not leave a seat folded
down unless you need to.
There is also important loading
information for off-road driving in
this manual. See “Loading Your
Vehicle for Off-Road Driving“
under Off-Road Driving on
page 9‑6. Two-Tiered Loading
Depending on the model of your
pick‐up, an upper load platform
can be created by positioning
three or four 5 cm (2 inches) by
15 cm (6 inches) wooden planks
across the width of the pickup
box. The planks must be
inserted in the pickup box
depressions.
When using this upper load
platform, be sure the load is
securely tied down to prevent it
from shifting. The load's center
of gravity should be positioned
in a zone over the rear axle.
The zone is located in the area
between the front of each wheel
well and the rear of each wheel
well. The center of gravity height
must not extend above the top
of the pickup box flareboard.
Black plate (40,1)Chevrolet Silverado Owner Manual - 2012
10-40 Vehicle Care
The vehicle should:
.Be placed so the headlamps
are 7.6 m (25 ft) from a
light‐colored wall.
.Have all four tires on a level
surface which is level all the way
to the wall.
.Be placed so it is perpendicular
to the wall.
.Not have any snow, ice, or mud
on it.
.Be fully assembled and all other
work stopped while headlamp
aiming is being performed.
.Be loaded with a full tank of
fuel and one person or 75 kg
(160 lbs) sitting on the
driver seat.
.Have the tires properly inflated.
.Have the spare tire in its proper
location in the vehicle.Headlamp aiming is done with the
vehicle's low-beam headlamps.
The high-beam headlamps will be
correctly aimed if the low-beam
headlamps are aimed properly.
To adjust the vertical aim:
1. Open the hood. See
Hood on
page 10‑52. Locate the aim dot on the lens of the low‐beam headlamp. 3. Record the distance from the
ground to the aim dot on the
low‐beam headlamp.
4. At a wall, measure from the
ground upward (A) to the
recorded distance from
Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall the width of the
vehicle at the height of the
mark in Step 4.
Black plate (55,1)Chevrolet Silverado Owner Manual - 2012
Vehicle Care 10-55
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 9‑6 andAdding a Snow
Plow or Similar Equipment on
page 9‑115 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.
Tire Sidewall Labeling
Useful information about a
tire is molded into the sidewall.
The examples show a typical
passenger and light truck 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 (56,1)Chevrolet Silverado Owner Manual - 2012
10-56 Vehicle Care
(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.
(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 10‑74.
(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 10‑62 andVehicle Load
Limits on page 9‑17.
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
Black plate (58,1)Chevrolet Silverado Owner Manual - 2012
10-58 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 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 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.
Black plate (59,1)Chevrolet Silverado Owner Manual - 2012
Vehicle Care 10-59
(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.
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.
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 10‑62.
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
Black plate (74,1)Chevrolet Silverado Owner Manual - 2012
10-74 Vehicle Care
Different Size Tires and
Wheels
If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, and electronic stability
control, the performance of these
systems can also 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 10‑72 andAccessories and
Modifications on page 10‑3 for
additional information.
Uniform Tire Quality
Grading
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width.
For example:
Treadwear 200 Traction AA
Temperature A
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires
by treadwear, traction, and
temperature performance.
This applies only to vehicles
sold in the United States.
The grades are molded on
the sidewalls of most passenger
Black plate (77,1)Chevrolet Silverado Owner Manual - 2012
Vehicle Care 10-77
Wheel Replacement
Replace any wheel that is bent,
cracked, or badly rusted or
corroded. If wheel nuts keep coming
loose, the wheel, wheel bolts and
wheel nuts should be replaced.
If the wheel leaks air, replace it.
Some aluminum wheels can be
repaired. See your dealer if any of
these conditions exist.
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.
Notice: 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. Whenever a wheel, wheel bolt,
or wheel nut is replaced on a dual
wheel setup, check the wheel nut
torque after 160, 1 600 and
10 000 km (100, 1,000 and 6,000 mi)
of driving. For proper torque,
see
“Wheel Nut Torque” under
Capacities and Specifications on
page 12‑2.
See If a Tire Goes Flat on
page 10‑79 for more information.
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.