2011 GMC ACADIA Owner's Manual

Black plate (41,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Vehicle Care 10-41
(F) Tire Size:A combination of
letters and numbers define a
tire's width, height, aspect ratio,
construction type, and service
description. The letter T as the
first character in the tire size
means the tire is for temporary
use only.
(G) 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.
Tire Designations
Tire Size
The following is an example
of a typical passenger vehicle
tire size.
(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 60, as shown in
item C of the illustration, it would
mean that the tire's sidewall is
60 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 (42,1)GMC Acadia/Acadia Denali Owner Manual - 2011
10-42 Vehicle Care
(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.
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
: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 10‑45.
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.

Black plate (43,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Vehicle Care 10-43
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 9‑12.
GAWR FRT
:Gross Axle
Weight Rating for the front axle.
See Vehicle Load Limits on
page 9‑12.
GAWR RR
:Gross Axle
Weight Rating for the rear axle.
See Vehicle Load Limits on
page 9‑12. 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 lbs).
See Vehicle Load Limits on
page 9‑12.
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.

Black plate (44,1)GMC Acadia/Acadia Denali Owner Manual - 2011
10-44 Vehicle Care
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 10‑45 andVehicle
Load Limits on page 9‑12.
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 10‑53.
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 on page 10‑57.

Black plate (45,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Vehicle Care 10-45
Vehicle Capacity Weight:
The number of designated
seating positions multiplied by
68 kg (150 lbs) plus the rated
cargo load. SeeVehicle Load
Limits on page 9‑12.
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 on page 9‑12.
Tire Pressure
Tires need the correct amount
of air pressure to operate
effectively.
Notice: Neither tire
underinflation nor
overinflation is good.
Underinflated tires, or
tires that do not have
enough air, can result in:
.Tire overloading and
over-heating which could
lead to a blowout.
.Premature or
irregular wear.
.Poor handling.
.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.
A vehicle-specific Tire and
Loading Information label
is attached to the vehicle.
This label shows the vehicle's
original equipment tires and the
correct inflation pressures for
the tires when they are cold.
The recommended cold tire
inflation pressure, shown on the
label, is the minimum amount of
air pressure needed to support
the vehicle's maximum load
carrying capacity.

Black plate (46,1)GMC Acadia/Acadia Denali Owner Manual - 2011
10-46 Vehicle Care
For additional information
regarding how much weight
the vehicle can carry, and an
example of the Tire and Loading
Information label, seeVehicle
Load Limits on page 9‑12.
How you load the vehicle affects
vehicle handling and ride
comfort. Never load the vehicle
with more weight than it was
designed to carry.
When to Check
Check the tires once a month or
more. Do not forget to check the
compact spare tire, if the vehicle
has one. The compact spare
should be at 420 kPa (60 psi).
For additional information
regarding the compact spare
tire, see Compact Spare Tire on
page 10‑82. How to Check
Use a good quality pocket-type
gauge to check tire pressure.
You cannot tell if the tires are
properly inflated simply by
looking at them. Radial tires may
look properly inflated even when
they are underinflated. Check
the tire's inflation pressure when
the tires are cold. Cold means
the vehicle has been sitting for
at least three hours or driven
no more than 1.6 km (1 mi).
Remove the valve cap from the
tire valve stem. Press the tire
gauge firmly onto the valve to
get a pressure measurement.
If the cold tire inflation pressure
matches the recommended
pressure on the Tire and
Loading Information label, no
further adjustment is necessary.
If the inflation pressure is low,
add air until you reach the
recommended amount.
If you overfill the tire, release air
by pushing on the metal stem
in the center of the tire valve.
Re‐check the tire pressure with
the tire gauge.
Be sure to put the valve caps
back on the valve stems.
They help prevent leaks by
keeping out dirt and moisture.

Black plate (47,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Vehicle Care 10-47
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your tires and
transmit tire pressure readings to
a receiver located in the vehicle.
Each tire, including the spare
(if provided), should be checked
monthly when cold and inflated to
the inflation pressure recommended
by the vehicle manufacturer on
the vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or
tire inflation pressure label, you
should determine the proper tire
inflation pressure for those tires.)
As an added safety feature, your
vehicle has been equipped with a
tire pressure monitoring system
(TPMS) that illuminates a low tirepressure telltale when one or
more of your tires is significantly
under‐inflated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires as
soon as possible, and inflate them
to the proper pressure. Driving on
a significantly under‐inflated tire
causes the tire to overheat and can
lead to tire failure. Under‐inflation
also reduces fuel efficiency and
tire tread life, and may affect the
vehicle's handling and stopping
ability.
Please note that the TPMS is
not a substitute for proper tire
maintenance, and it is the driver's
responsibility to maintain correct
tire pressure, even if under‐inflation
has not reached the level to trigger
illumination of the TPMS low tire
pressure telltale.
Your vehicle has also been
equipped with a TPMS malfunction
indicator to indicate when the
system is not operating properly.The TPMS malfunction indicator is
combined with the low tire pressure
telltale. When the system detects a
malfunction, the telltale will flash for
approximately one minute and then
remain continuously illuminated.
This sequence will continue upon
subsequent vehicle start‐ups as
long as the malfunction exists.
When the malfunction indicator
is illuminated, the system may
not be able to detect or signal low
tire pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires or
wheels on the vehicle that prevent
the TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow
the TPMS to continue to function
properly.
See
Tire Pressure Monitor
Operation on page 10‑48 for
additional information.

Black plate (48,1)GMC Acadia/Acadia Denali Owner Manual - 2011
10-48 Vehicle Care
Federal Communications
Commission (FCC) and
Industry Canada
SeeRadio Frequency Statement on
page 13‑20 for information
regarding Part 15 of the Federal
Communications Commission
(FCC) rules and Industry Canada
Standards RSS-210/220/310.
Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn
the driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly, if the vehicle
has one. The TPMS sensors
monitor the air pressure in the
tires and transmits the tire pressure
readings to a receiver located in
the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.
If the warning light comes on, stop
as soon as possible and inflate
the tires to the recommended
pressure shown on the tire loading
information label. See Vehicle Load
Limits on page 9‑12.
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires
are inflated to the correct inflation
pressure. Using the DIC, tire
pressure levels can be viewed. For additional information and
details about the DIC operation
and displays see
Driver Information
Center (DIC) (With DIC Buttons) on
page 5‑25 orDriver Information
Center (DIC) (Without DIC Buttons)
on page 5‑30 andTire Messages on
page 5‑44.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven.
This could be an early indicator that
the air pressure is getting low and
needs to be inflated to the proper
pressure.
A Tire and Loading Information
label shows the size of the original
equipment tires and the correct
inflation pressure for the tires when
they are cold. See Vehicle Load
Limits on page 9‑12, for an example
of the Tire and Loading Information
label and its location. Also see Tire
Pressure on page 10‑45.