2009 GMC ENVOY tire size

Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may keep the airbag system from
working properly. Changing or moving any parts of
the front seats, safety belts, the airbag sensing and
diagnostic module, steering wheel, instrument panel,
roof-rail airbag modules, ceiling headliner or pillar
garnish trim, rearview mirror, front sensors, rollover
sensor module, or airbag wiring can affect the
operation of the airbag system.
In addition, your vehicle has 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 alsointerfere 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 1-64.
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.
SeeCustomer Satisfaction Procedure on page 7-2.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-72
for additional important information.
Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether this
will affect my airbag system?
A:If you have questions, call Customer Assistance.
The phone numbers and addresses for Customer
Assistance are in Step Two of the Customer
Satisfaction Procedure in this manual. SeeCustomer
Satisfaction Procedure on page 7-2.
In addition, your dealer/retailer and the service manual
have information about the location of the airbag sensors,
sensing and diagnostic module and airbag wiring.
1-69

Your Driving, the Road, and
the Vehicle
Driving for Better Fuel Economy
Driving habits can affect fuel mileage. Here are some
driving tips to get the best fuel economy possible.
Avoid fast starts and accelerate smoothly.
Brake gradually and avoid abrupt stops.
Avoid idling the engine for long periods of time.
When road and weather conditions are appropriate,
use cruise control, if equipped.
Always follow posted speed limits or drive more
slowly when conditions require.
Keep vehicle tires properly inated.
Combine several trips into a single trip.
Replace the vehicle’s tires with the same TPC Spec
number molded into the tire’s sidewall near the size.
Follow recommended scheduled maintenance.
Defensive Driving
Defensive driving means “always expect the
unexpected.” The rst step in driving defensively is to
wear your safety belt — SeeSafety Belts: They Are for
Everyone on page 1-13.
{CAUTION:
Assume that other road users (pedestrians,
bicyclists, and other drivers) are going to be
careless and make mistakes. Anticipate what they
might do and be ready. In addition:
Allow enough following distance between you
and the driver in front of you.
Focus on the task of driving.
Driver distraction can cause collisions resulting in
injury or possible death. These simple defensive
driving techniques could save your life.
4-2

Tire and Loading Information Label
A vehicle specic Tire and Loading Information
label is attached to the center pillar (B-pillar).
With the driver’s door open, you will nd the
label attached below the door lock post (striker).The Tire and Loading Information label shows the
number of occupant seating positions (A), and the
maximum vehicle capacity weight (B) in kilograms
and pounds.
The Tire and Loading Information label also shows
the size of the original equipment tires (C) and
the recommended cold tire ination pressures (D).
For more information on tires and ination see
Tires on page 5-53andInflation - Tire Pressure on
page 5-60.
There is also important loading information on the
vehicle Certication/Tire label. It tells you the
Gross Vehicle Weight Rating (GVWR) and
the Gross Axle Weight Rating (GAWR) for the
front and rear axle. See “Certication/Tire Label”
later in this section.
Label Example
4-32

Certication/Tire Label
A vehicle specic Certication/Tire label is found on
the rear edge of the driver’s door. The label shows
the size of your vehicle’s original tires and the
ination pressures needed to obtain the gross
weight capacity of your vehicle. This is called Gross
Vehicle Weight Rating (GVWR). The GVWR
includes the weight of the vehicle, all occupants,
fuel, cargo, and trailer tongue weight, if pulling a
trailer.The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR). To nd
out the actual loads on your front and rear axles,
you need to go to a weigh station and weigh your
vehicle. Your dealer can help you with this. Be sure
to spread out your load equally on both sides of the
centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, you should
spread it out.
Similar appearing vehicles may have different
GVWRs and capacity weights. Please note your
vehicle’s Certication/Tire label or consult
your dealer for additional details.
4-36

Tire Pressure Monitor Operation.....................5-64
Tire Inspection and Rotation...........................5-68
When It Is Time for New Tires.......................5-69
Buying New Tires.........................................5-70
Different Size Tires and Wheels......................5-72
Uniform Tire Quality Grading..........................5-72
Wheel Alignment and Tire Balance..................5-74
Wheel Replacement......................................5-74
Tire Chains..................................................5-76
If a Tire Goes Flat........................................5-76
Tire Sealant and Compressor Kit....................5-77
Tire Sealant and Compressor Kit Storage.........5-87
Changing a Flat Tire.....................................5-88
Removing the Spare Tire and Tools................5-89
Removing the Flat Tire and Installing the
Spare Tire................................................5-92
Secondary Latch System...............................5-97
Storing a Flat or Spare Tire and Tools...........5-100
Spare Tire.................................................5-102
Appearance Care..........................................5-103
Interior Cleaning.........................................5-103
Fabric/Carpet..............................................5-104
Leather......................................................5-105
Instrument Panel, Vinyl, and Other Plastic
Surfaces.................................................5-106Care of Safety Belts....................................5-106
Weatherstrips.............................................5-106
Washing Your Vehicle..................................5-107
Cleaning Exterior Lamps/Lenses....................5-107
Finish Care................................................5-108
Windshield, Backglass, and Wiper Blades.......5-108
Aluminum Wheels.......................................5-109
Tires.........................................................5-109
Sheet Metal Damage...................................5-109
Finish Damage...........................................5-110
Underbody Maintenance...............................5-110
Chemical Paint Spotting...............................5-110
Vehicle Identication.....................................5-111
Vehicle Identication Number (VIN)................5-111
Service Parts Identication Label...................5-111
Electrical System..........................................5-112
Add-On Electrical Equipment.........................5-112
Headlamps.................................................5-112
Windshield Wiper Fuses...............................5-112
Power Windows and Other Power Options......5-112
Fuses and Circuit Breakers..........................5-113
Engine Compartment Fuse Block...................5-113
Rear Underseat Fuse Block..........................5-116
Capacities and Specications........................5-120
Section 5 Service and Appearance Care
5-2

Low-Prole Performance Tire
If your vehicle has P255/50R20 size tires, they
are classied as low-prole performance tires.
These tires are designed for very responsive
driving on wet or dry pavement. You may
also notice more road noise with low-prole
performance tires and that they tend to wear
faster.
Notice:If the vehicle has low-prole tires,
they are more susceptible to damage from road
hazards or curb impact than standard prole
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 ination
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 illustration is an example
of a typical P-Metric tire sidewall.
(A) Tire Size
:The tire size code is a combination
of letters and numbers used to dene 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.
Passenger (P-Metric) Tire
5-54

(B) TPC Spec (Tire Performance Criteria
Specication):Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications 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 Identication Number (TIN)
:The letters
and numbers following DOT code are the Tire
Identication 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, seeUniform Tire Quality Grading on
page 5-72.
(G) Maximum Cold Ination Load Limit
:Maximum load that can be carried and the
maximum pressure needed to support that load.
For information on recommended tire pressure
seeInflation - Tire Pressure on page 5-60
andLoading the Vehicle on page 4-31.
5-55

Tire Size
The following examples show the different parts of
a tire size.
(A) Passenger (P-Metric) Tire
:The United States
version of a metric tire sizing system. The letter P
as the rst 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 passenger (P-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) Service Description
:The service description
indicates the load range and speed rating of a
tire. The load index can range from 1 to 279.
Speed ratings range from A to Z.
Passenger (P-Metric) Tire
5-56