2008 PONTIAC GRAND PRIX Tires

Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer
but it will take much more effort.
Variable Effort Steering
If your vehicle has this steering system, the system
provides less steering effort for parking and when driving
at speeds below 20 mph (32 km/h). Steering effort will
increase at higher speeds for improved road feel.
Steering Tips
It is important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned
on the news happen on curves. Here is why:
Experienced driver or beginner, each of us is subject
to the same laws of physics when driving on curves.
The traction of the tires against the road surface
makes it possible for the vehicle to change its path
when you turn the front wheels. If there is no traction,
inertia will keep the vehicle going in the same direction.
If you have ever tried to steer a vehicle on wet ice,
you will understand this.The traction you can get in a curve depends on the
condition of the tires and the road surface, the angle at
which the curve is banked, and your speed. While you
are in a curve, speed is the one factor you can control.
Suppose you are steering through a sharp curve.
Then you suddenly apply the brakes. Both control
systems — steering and braking — have to do their
work where the tires meet the road. Unless you have
antilock brakes, adding the hard braking can demand
too much of those places. You can lose control.
The same thing can happen if you are steering through
a sharp curve and you suddenly accelerate. Those
two control systems — steering and acceleration — can
overwhelm those places where the tires meet the
road and make you lose control. SeeTraction Control
System (TCS) on page 4-6orEnhanced Traction
System (ETS) on page 4-7.
What should you do if this ever happens? Ease up on
the brake or accelerator pedal, steer the vehicle the way
you want it to go, and slow down.
Speed limit signs near curves warn that you should
adjust your speed. Of course, the posted speeds
are based on good weather and road conditions. Under
less favorable conditions you will want to go slower.
If you need to reduce your speed as you approach
a curve, do it before you enter the curve, while the
front wheels are straight ahead.
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Off-Road Recovery
You may nd that your vehicle’s right wheels have
dropped off the edge of a road onto the shoulder while
you are driving.
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease off the
accelerator and then, if there is nothing in the way, steer
so that your vehicle straddles the edge of the pavement.
You can turn the steering wheel up to one-quarter turn
until the right front tire contacts the pavement edge. Then
turn the steering wheel to go straight down the roadway.
Passing
Passing another vehicle on a two-lane road can be
dangerous. To reduce the risk of danger while passing,
we suggest the following tips:
Look down the road, to the sides, and to crossroads
for situations that might affect a successful pass.
If in doubt, wait.
Watch for traffic signs, pavement markings, and
lines that could indicate a turn or an intersection.
Never cross a solid or double-solid line on your
side of the lane.
Do not get too close to the vehicle you want to
pass. Doing so can reduce your visibility.
Wait your turn to pass a slow vehicle.
When you are being passed, ease to the right.
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.
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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 your 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.
A cornering skid is best handled by easing your foot off
the accelerator pedal.
If you do not have the Enhanced Traction System (ETS)
or the Traction Control System (TCS), or if the system
is off, then an acceleration skid is also best handled
by easing your foot off the accelerator pedal. See
Enhanced Traction System (ETS) on page 4-7or
Traction Control System (TCS) on page 4-6.
If your 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,
your 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,
you will want to slow down and adjust your driving to
these conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
While driving on a surface with reduced traction, try
your best 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 may not realize the surface is slippery until
your 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.
If you have the Antilock Brake System (ABS),
remember: It helps avoid only the braking skid. If you
do not have ABS, then in a braking skid, where the
wheels are no longer rolling, release enough pressure
on the brakes to get the wheels rolling again. This
restores steering control. Push the brake pedal down
steadily when you have to stop suddenly. As long as
the wheels are rolling, you will have steering control.
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Hydroplaning
Hydroplaning is dangerous. Water can build up
under your 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 your 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 uid reservoir lled.
Have good tires with proper tread depth.
SeeTires on page 5-62.
Before Leaving on a Long Trip
To prepare your vehicle for a long trip, consider having
it serviced by your dealer/retailer before departing.
Things to check on your own include:
Windshield Washer Fluid:Reservoir full?
Windows clean — inside and outside?
Wiper Blades:In good shape?
Fuel, Engine Oil, Other Fluids:All levels checked?
Lamps:Do they all work and are lenses clean?
Tires:Are treads good? Are tires inated to
recommended pressure?
Weather and Maps:Safe to travel?
Have up-to-date maps?
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Highway Hypnosis
Always be alert and pay attention to your surroundings
while driving. If you become tired or sleepy, nd a
safe place to park your vehicle and rest.
Other driving tips include:
Keep the vehicle well ventilated.
Keep interior temperature cool.
Keep your eyes moving — scan the road
ahead and to the sides.
Check the rearview mirror and vehicle
instruments often.
Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on at or rolling terrain. Tips for driving
in these conditions include:
Keep your vehicle serviced and in good shape.
Check all uid levels and brakes, tires, cooling
system, and transmission.
Going down steep or long hills, shift to a
lower gear.
{CAUTION:
If you do not shift down, the brakes could get
so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Shift down
to let the engine assist the brakes on a steep
downhill slope.
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{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. The brakes will have
to do all the work of slowing down and they
could get so hot that they would not work well.
You would then have poor braking or even
none going down a hill. You could crash.
Always have the engine running and your
vehicle in gear when you go downhill.
Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
Top of hills: Be alert — something could be in your
lane (stalled car, accident).
Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You might want to put winter emergency
supplies in your trunk.
Include an ice scraper, a small brush or broom,
a supply of windshield washer uid, a rag, some
winter outer clothing, a small shovel, a ashlight,
a red cloth, and a couple of reective warning triangles.
And, if you will be driving under severe conditions,
include a small bag of sand, a piece of old carpet,
or a couple of burlap bags to help provide traction.
Be sure you properly secure these items in your vehicle.
Also seeTires on page 5-62.
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Driving on Snow or Ice
Most of the time, those places where the tires meet the
road probably have good traction.
However, if there is snow or ice between the tires and the
road, you can have a very slippery situation. You have a
lot less traction, or grip, and need to be very careful.
What is the worst time for this? Wet ice. Very cold snow
or ice can be slick and hard to drive on.But wet ice can be even more trouble because it can
offer the least traction of all. You can get wet ice when it
is about freezing, 32°F (0°C), and freezing rain begins
to fall. Try to avoid driving on wet ice until salt and sand
crews can get there.
Whatever the condition — smooth ice, packed, blowing,
or loose snow — drive with caution.
If your vehicle has the Traction Control System (TCS)
or the Enhanced Traction System (ETS), it will improve
your ability to accelerate when driving on a slippery
road. Even though your vehicle has a traction system,
slow down and adjust your driving to the road conditions.
Under certain conditions, you might want to turn
the TCS or ETS off, such as when driving through
deep snow and loose gravel, to help maintain vehicle
motion at lower speeds. SeeTraction Control System
(TCS) on page 4-6orEnhanced Traction System (ETS)
on page 4-7.
If your vehicle does not have TCS or ETS, accelerate
gently. Try not to break the fragile traction. If you
accelerate too fast, the drive wheels will spin and
polish the surface under the tires even more.
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Then, shut the engine off and close the window almost all
the way to preserve the heat. Start the engine again and
repeat this only when you feel really uncomfortable from
the cold. But do it as little as possible. Preserve the fuel
as long as you can. To help keep warm, you can get out
of the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free your
vehicle when stuck in sand, mud, ice, or snow. See
Rocking Your Vehicle to Get It Out on page 4-22.
If your vehicle has a traction system, it can often help
to free a stuck vehicle. Refer to your vehicle’s traction
system in the Index. If the stuck condition is too
severe for the traction system to free the vehicle, turn
the traction system off and use the rocking method.
{CAUTION:
If you let your vehicle’s tires spin at high speed,
they can explode, and you or others could be
injured. The vehicle can overheat, causing an
engine compartment re or other damage.
Spin the wheels as little as possible and avoid
going above 35 mph (55 km/h) as shown on the
speedometer.
For information about using tire chains on your vehicle,
seeTire Chains on page 5-84.
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