2007 GMC SIERRA CLASSIC tires

Try not to pass more than one vehicle at a time
on two-lane roads. Reconsider before passing
the next vehicle.
Do not overtake a slowly moving vehicle too
rapidly. Even though the brake lamps are not
ashing, it may be slowing down or starting
to turn.
If you are being passed, make it easy for the
following driver to get ahead of you. Perhaps
you can ease a little 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.
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,
your 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 have the Traction Assist System (TAS),
remember: It helps avoid only the acceleration
skid. SeeTraction Assist System (TAS) on
page 363. If you do not have this system, or if the
system is off, then an acceleration skid is also
best handled by easing your foot off the
accelerator pedal.
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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.
Remember: Any Anti-Lock Brake System (ABS)
helps avoid only the braking skid.Off-Road Driving
This off-road guide is for vehicles that have
four-wheel drive. Also, seeBraking on page 360.
If your vehicle does not have four-wheel drive
or is equipped with 20-inch tire/wheel assemblies,
you should not drive off-road unless you are on
a level, solid surface.
Off-road driving can be great fun. But it does have
some denite hazards. The greatest of these is
the terrain itself.
“Off-roading” means you have left the great
North American road system behind. Traffic lanes
are not marked. Curves are not banked. There
are no road signs. Surfaces can be slippery, rough,
uphill, or downhill. In short, you have gone right
back to nature.
Off-road driving involves some new skills. And
that is why it is very important that you read this
guide. You will nd many driving tips and
suggestions. These will help make your off-road
driving safer and more enjoyable.
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Loading Your Vehicle for Off-Road
Driving
{CAUTION:
Cargo on the load oor piled higher
than the seatbacks can be thrown
forward during a sudden stop. You or
your passengers could be injured.
Keep cargo below the top of the
seatbacks.
Unsecured cargo on the load oor can
be tossed about when driving over
rough terrain. You or your passengers
can be struck by ying objects.
Secure the cargo properly.
Heavy loads on the roof raise the
vehicle’s center of gravity, making it
more likely to roll over. You can be
seriously or fatally injured if the
vehicle rolls over. Put heavy loads
inside the cargo area, not on the roof.
Keep cargo in the cargo area as far
forward and low as possible.There are some important things to remember
about how to load your vehicle.
The heaviest things should be on the load
oor and forward of the rear axle. Put
heavier items as far forward as you can.
Be sure the load is secured properly, so
driving on the off-road terrain does not
toss things around.
You will nd other important information in this
manual. SeeLoading Your Vehicle on page 409
andTires on page 543.
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Driving Across an Incline
Sooner or later, an off-road trail will probably go
across the incline of a hill. If this happens,
you have to decide whether to try to drive across
the incline. Here are some things to consider:
A hill that can be driven straight up or down
may be too steep to drive across. When you go
straight up or down a hill, the length of the
wheel base — the distance from the front
wheels to the rear wheels — reduces the
likelihood the vehicle will tumble end over end.
But when you drive across an incline, the much
more narrow track width — the distance
between the left and right wheels — may not
prevent the vehicle from tilting and rolling over.
Also, driving across an incline puts more weight
on the downhill wheels. This could cause a
downhill slide or a rollover.
Surface conditions can be a problem when you
drive across a hill. Loose gravel, muddy spots,
or even wet grass can cause your tires to slip
sideways, downhill. If the vehicle slips
sideways, it can hit something that will
trip it — a rock, a rut, etc. — and roll over.
Hidden obstacles can make the steepness of
the incline even worse. If you drive across a
rock with the uphill wheels, or if the downhill
wheels drop into a rut or depression, your
vehicle can tilt even more.
For reasons like these, you need to decide
carefully whether to try to drive across an incline.
Just because the trail goes across the incline
does not mean you have to drive it. The last
vehicle to try it might have rolled over.
{CAUTION:
Driving across an incline that is too steep
will make your vehicle roll over. You could
be seriously injured or killed. If you have
any doubt about the steepness of the
incline, do not drive across it. Find another
route instead.
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Driving in Mud, Sand, Snow, or Ice
When you drive in mud, snow, or sand, your wheels
will not get good traction. You cannot accelerate as
quickly, turning is more difficult, and you will need
longer braking distances. If your vehicle has
four-wheel drive, seeFour-Wheel Drive on
page 153for transfer case mode selection.
It is best to use a low gear when you are in
mud —the deeper the mud, the lower the gear.
In really deep mud, the idea is to keep your vehicle
moving so you do not get stuck.
When you drive on sand, you will sense a change
in wheel traction. But it will depend upon how
loosely packed the sand is. On loosely packed
sand, such as on beaches or sand dunes,
your tires will tend to sink into the sand. This has
an effect on steering, accelerating, and braking.
Drive at a reduced speed and avoid sharp turns
or abrupt maneuvers.Hard packed snow and ice offer the worst tire
traction. On these surfaces, it is very easy to lose
control. On wet ice, for example, the traction is so
poor that you will have difficulty accelerating. And if
you do get moving, poor steering and difficult
braking can cause you to slide out of control.
{CAUTION:
Driving on frozen lakes, ponds, or rivers
can be dangerous. Underwater springs,
currents under the ice, or sudden thaws
can weaken the ice. Your vehicle could
fall through the ice and you and your
passengers could drown. Drive your
vehicle on safe surfaces only.
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Driving in Water
Heavy rain can mean ash ooding, and ood
waters demand extreme caution.
Find out how deep the water is before you drive
through it. If it is deep enough to cover the wheel
hubs, axles, or exhaust pipe, do not try it — you
probably will not get through. Also, water that deep
can damage the axle and other vehicle parts.
If the water is not too deep, drive slowly through it.
At faster speeds, water splashes on the ignition
system and your vehicle can stall. Stalling can also
occur if you get the tailpipe under water. And,
as long as the tailpipe is under water, you will
never be able to start the engine. When you go
through water, remember that when the brakes get
wet, it may take you longer to stop.{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your
vehicle downstream and you and your
passengers could drown. If it is only
shallow water, it can still wash away the
ground from under your tires, and you
could lose traction and roll the vehicle
over. Do not drive through rushing water.
SeeDriving in Rain and on Wet Roads on page 392
for more information on driving through water.
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After Off-Road Driving
Remove any brush or debris that has collected
on the underbody, chassis, or under the hood.
These accumulations can be a re hazard.
After operation in mud or sand, have the brake
linings cleaned and checked. These substances
can cause glazing and uneven braking. Check the
body structure, steering, suspension, wheels,
tires, and exhaust system for damage. Also, check
the fuel lines and cooling system for any leakage.
Your vehicle will require more frequent service
due to off-road use. Refer to the Maintenance
Schedule for additional information.
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to
be impaired — by alcohol or drugs, with night
vision problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust the inside rearview mirror to reduce the
glare from headlamps behind you.
Since you cannot see as well, you may need
to slow down and keep more space between
you and other vehicles.
Slow down, especially on higher speed roads.
Your vehicle’s headlamps can light up only so
much road ahead.
In remote areas, watch for animals.
If you are tired, pull off the road in a safe
place and rest.
No one can see as well at night as in the daytime.
But as we get older these differences increase.
A 50-year-old driver may require at least twice as
much light to see the same thing at night as a
20-year-old.
What you do in the daytime can also affect your
night vision. For example, if you spend the
day in bright sunshine you are wise to wear
sunglasses. Your eyes will have less trouble
adjusting to night. But if you are driving, do not
wear sunglasses at night. They may cut down on
glare from headlamps, but they also make a
lot of things invisible.
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And, if your tires do not have much tread left,
you will get even less traction. It is always wise to
go slower and be cautious if rain starts to fall
while you are driving. The surface may get wet
suddenly when your reexes are tuned for driving
on dry pavement. If your vehicle has four-wheel
drive, seeFour-Wheel Drive on page 153for
transfer case mode selection.
The heavier the rain, the harder it is to see.
Even if your windshield wiper blades are in good
shape, a heavy rain can make it harder to see
road signs and traffic signals, pavement markings,
the edge of the road, and even people walking.
It is wise to keep your wiping equipment in
good shape and keep your windshield washer
uid reservoir lled with washer uid. Replace your
windshield wiper inserts when they show signs
of streaking or missing areas on the windshield,
or when strips of rubber start to separate from
the inserts.
{CAUTION:
Wet brakes can cause accidents. They
may not work as well in a quick stop and
may cause pulling to one side. You could
lose control of the vehicle.
After driving through a large puddle of
water or a car wash, apply your brake pedal
lightly until your brakes work normally.
Driving too fast through large water puddles or
even going through some car washes can cause
problems, too. The water may affect your brakes.
Try to avoid puddles. But if you cannot, try to slow
down before you hit them.
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