Black plate (6,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-6 Driving and Operating
Ease off the accelerator and
then, if there is nothing in the
way, steer so that the vehicle
straddles the edge of the pavement.
Turn the steering wheel 8 to 13 cm
(3 to 5 in), about one-eighth turn,
until the right front tire contacts
the pavement edge. Then turn the
steering wheel to go straight down
the roadway.
Loss of Control
Let us review what driving experts
say about what happens when the
three control systems—brakes,
steering, and acceleration —do not
have enough friction where the tires
meet the road to do what the driver
has asked.
In any emergency, do not give up.
Keep trying to steer and constantly
seek an escape route or area of
less danger.
Skidding
In a skid, a driver can lose control of
the vehicle. Defensive drivers avoid
most skids by taking reasonable
care suited to existing conditions,
and by not overdriving those
conditions. But skids are always
possible.
The three types of skids
correspond to the vehicle's three
control systems. In the braking skid,
the wheels are not rolling. In the
steering or cornering skid, too much
speed or steering in a curve causes
tires to slip and lose cornering force.
And in the acceleration skid, too
much throttle causes the driving
wheels to spin.
If the vehicle starts to slide, ease
your foot off the accelerator pedal
and quickly steer the way you
want the vehicle to go. If you start
steering quickly enough, the vehicle
may straighten out. Always be ready
for a second skid if it occurs. Of course, traction is reduced when
water, snow, ice, gravel, or other
material is on the road. For safety,
slow down and adjust your driving
to these conditions. It is important
to slow down on slippery surfaces
because stopping distance is longer
and vehicle control more limited.
While driving on a surface with
reduced traction, 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. You might
not realize the surface is slippery
until the vehicle is skidding. 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.
Remember: Antilock brakes help
avoid only the braking skid.
Black plate (7,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-7
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.(Continued)
WARNING (Continued)
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.
.Keep the windshield washer fluid
reservoir filled.
.Have good tires with proper
tread depth. See
Tires on
page 10‑38.
.Turn off cruise control.
Black plate (54,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-54 Driving and Operating
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 theGVWR (Gross Vehicle Weight
Rating) or the 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 9‑12 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 there
are, 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 9‑24.
Black plate (39,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Vehicle Care 10-39
Tire Sidewall Labeling
Useful information about a
tire is molded into its sidewall.
The examples below 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 10‑57.
Black plate (40,1)GMC Acadia/Acadia Denali Owner Manual - 2011
10-40 Vehicle Care
(G) Maximum Cold Inflation
Load Limit
:Maximum load
that can be carried and the
maximum pressure needed
to support that load.
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 10‑82 andIf a Tire Goes
Flat on page 10‑61.
(C) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT (Department
of Transportation) code is 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 10‑45.
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 (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 (55,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Vehicle Care 10-55
GM recommends replacing
tires in sets of four. This is
because uniform tread depth
on all tires will help keep the
vehicle performing most like it
did when the tires were new.
Replacing less than a full set
of tires can affect the braking
and handling performance of
the vehicle. SeeTire Inspection
on page 10‑51 andTire Rotation
on page 10‑52 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 could cause you
to lose control while driving.
If you mix tires of different
sizes, brands, or types
(radial and bias-belted tires),
the vehicle may not handle
properly, and you could have
a crash. Using tires of different
sizes, brands, or types may
also cause damage to the
vehicle. Be sure to use the
correct size, brand, and type
of tires on all wheels. It is all
right to drive with the compact
spare temporarily, as it was
developed for use on the
vehicle. See Compact Spare
Tire on page 10‑82.{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 you must replace the vehicle's
tires with those that do not
have a TPC Spec number,
make sure they are the same
size, load range, speed rating,
and construction type (radial
and bias‐belted tires) as the
vehicle's original tires.