Black plate (5,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-5
Off-Road Recovery
The vehicle's right wheels can
drop off the edge of a road onto
the shoulder while driving.
Follow these tips:
1. Ease off the accelerator andthen, if there is nothing in the
way, steer the vehicle so that it
straddles the edge of the
pavement. 2. Turn the steering wheel about
one-eighth of a turn, until the
right front tire contacts the
pavement edge.
3. Then turn the steering wheel to go straight down the roadway.
Loss of Control
Skidding
There are three types of skids that
correspond to the vehicle's three
control systems:
.Braking Skid —wheels are
not rolling.
.Steering or Cornering
Skid —too much speed or
steering in a curve causes tires
to slip and lose cornering force.
.Acceleration Skid —too much
throttle causes the driving
wheels to spin. Defensive drivers avoid most skids
by taking reasonable care suited to
existing conditions, and by not
overdriving those conditions.
But skids are always possible.
If the vehicle starts to slide, follow
these suggestions:
.Ease your foot off the
accelerator pedal and quickly
steer the way you want the
vehicle to go. The vehicle may
straighten out. Be ready for a
second skid if it occurs.
.Slow down and adjust your
driving according to weather
conditions. Stopping distance
can be longer and vehicle
control can be affected when
traction is reduced by water,
snow, ice, gravel, or other
material on the road.
Learn to recognize warning
clues
—such as enough water,
ice, or packed snow on the
road to make a mirrored
surface —and slow down
when you have any doubt.
Black plate (6,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-6 Driving and Operating
.Try to avoid sudden steering,
acceleration, or braking,
including reducing vehicle
speed by shifting to a lower
gear. Any sudden changes
could cause the tires to slide.
Remember: Antilock brakes help
avoid only the braking skid.
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these
types of driving conditions and
avoid driving through large
puddles and deep‐standing or
flowing water.
{WARNING
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous.
Water can build up under the
vehicle's tires so they actually ride
on the water. This can happen if the
road is wet enough and you are
going fast enough. When the
vehicle is hydroplaning, it has little
or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping
equipment in good shape.
Black plate (51,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-51
If a weight-carrying hitch or a
weight-distributing hitch is being
used, the trailer tongue (A) should
weigh 10‐15 percent of the total
loaded trailer weight (B).
After loading the trailer, weigh the
trailer and then the tongue,
separately, to see if the weights are
proper. If they are not, adjustments
might be made by moving some
items around in the trailer.
Trailering may be limited by the
vehicle's ability to carry tongue
weight. Tongue weight cannot cause
the vehicle to exceed the GVWR
(Gross Vehicle Weight Rating) orthe RGAWR (Rear Gross Axle
Weight Rating). The effect of
additional weight may reduce the
trailering capacity more than the
total of the additional weight.
It is important that the vehicle
does not exceed any of its
ratings
—GCWR, GVWR, RGAWR,
Maximum Trailer Rating or Tongue
Weight. The only way to be sure it is
not exceeding any of these ratings
is to weigh the vehicle and trailer.
Total Weight on the
Vehicle's Tires
Inflate the vehicle's tires to the
upper limit for cold tires. These
numbers can be found on the
Certification label or see Vehicle
Load Limits on page 9‑10 for more
information. Do not go over the
GVW limit for the vehicle, or the
GAWR, including the weight of the
trailer tongue. If using a weight
distributing hitch, do not go over the
rear axle limit before applying the
weight distribution spring bars.
Towing Equipment
Hitches
It is important to have the correct
hitch equipment. Crosswinds, large
trucks going by, and rough roads
are a few reasons why the right
hitch is needed.
.The rear bumper on the vehicle
is not intended for hitches.
Do not attach rental hitches or
other bumper-type hitches to it.
Use only a frame-mounted
hitch that does not attach to the
bumper.
.Will any holes be made in the
body of the vehicle when the
trailer hitch is installed? If so,
then be sure to seal the holes
when the hitch is removed. If the
holes are not sealed, dirt, water,
and deadly carbon monoxide
(CO) from the exhaust may get
into the vehicle. See Engine
Exhaust on page 9‑22.
Black plate (38,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-38 Vehicle Care
Tire Sidewall Labeling
Useful information about a
tire is molded into its sidewall.
The examples show a typical
passenger vehicle tire and a
compact spare tire sidewall.
Passenger (P‐Metric) Tire Example
(A) Tire Size:The tire size 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.
(D) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT (Department
of Transportation) 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 10‑54.
(G) Maximum Cold Inflation
Load Limit
:Maximum load
that can be carried and the
maximum pressure needed to
support that load.
Black plate (39,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Vehicle Care 10-39
Compact Spare Tire Example
(A) Tire Ply Material:The type
of cord and number of plies in
the sidewall and under the tread.
(B) Temporary Use Only
:
The compact spare tire or
temporary use tire has a tread
life of approximately 5 000 km
(3,000 mi) and should not be
driven at speeds over 105 km/h
(65 mph). The compact spare
tire is for emergency use when a regular road tire has lost air
and gone flat. If the vehicle
has a compact spare tire,
see
Compact Spare Tire on
page 10‑77 andIf a Tire Goes
Flat on page 10‑58.
(C) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT (Department
of Transportation) 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.
(D) Maximum Cold Inflation
Load Limit
:Maximum load
that can be carried and the
maximum pressure needed to
support that load. (E) Tire Inflation
:The
temporary use tire or compact
spare tire should be inflated to
420 kPa (60 psi). For more
information on tire pressure and
inflation see Tire Pressure on
page 10‑44.
(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.
Black plate (40,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-40 Vehicle Care
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. (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 kPa (kilopascal)
or psi (pounds per square inch).
Black plate (44,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-44 Vehicle Care
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
overheating 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.
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 on page 9‑10. How the vehicle is loaded
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 the
compact spare tire, if the
vehicle has one. The cold
compact spare should be at
420 kPa (60 psi). For additional
information regarding the
compact spare tire, see
Compact Spare Tire on
page 10‑77.
How to Check
Use a good quality pocket-type
gauge to check tire pressure.
Proper tire inflation cannot be
determined by looking at the tire.
Check the tire inflation pressure
when the tires are cold, meaning
Black plate (53,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Vehicle Care 10-53
Braking and handling
performance may be adversely
affected if all the tires are not
replaced at the same time.
SeeTire Inspection on
page 10‑50 andTire Rotation on
page 10‑50 for information on
proper tire rotation.
{WARNING
Tires could explode during
improper service. Attempting
to mount or dismount a tire
could cause injury or death.
Only your dealer or authorized
tire service center should
mount or dismount the tires.
{WARNING
Mixing tires of different sizes,
brands, or types may cause
loss of control of the vehicle,
resulting in a crash or other
vehicle damage. Use the
correct size, brand, and type
of tires on all wheels.
{WARNING
Using bias-ply tires on the
vehicle may cause the wheel
rim flanges to develop cracks
after many miles of driving.
A tire and/or wheel could fail
suddenly and cause a crash.
Use only radial-ply tires with
the wheels on the vehicle. If the vehicle tires must be
replaced with a tire that does not
have a TPC Spec number, make
sure they are the same size,
load range, speed rating, and
construction (radial) as the
original tires.
Vehicles that have a tire
pressure monitoring system
could give an inaccurate
low‐pressure warning if
non‐TPC Spec rated tires are
installed. See
Tire Pressure
Monitor System on page 10‑45.
The Tire and Loading
Information label indicates the
original equipment tires on the
vehicle. See Vehicle Load Limits
on page 9‑10 for the label
location and more information
about the Tire and Loading
Information label.