2003 GMC ENVOY Owner's Manual

Here are some tips on night driving.
·Drive defensively.
·Don't drink and drive.
·Since you can't 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
headlamps can light up only so much road ahead.
·In remote areas, watch for animals.
·If you're 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're driving, don't wear sunglasses at night. They may
cut down on glare from headlamps, but they also
make a lot of things invisible.You can be temporarily blinded by approaching
headlamps. It can take a second or two, or even several
seconds, for your eyes to readjust to the dark. When
you are faced with severe glare (as from a driver
who doesn't lower the high beams, or a vehicle with
misaimed headlamps), slow down a little. Avoid staring
directly into the approaching headlamps.
Keep your windshield and all the glass on your vehicle
clean Ð inside and out. Glare at night is made much
worse by dirt on the glass. Even the inside of the glass
can build up a ®lm caused by dust. Dirty glass makes
lights dazzle and ¯ash more than clean glass would,
making the pupils of your eyes contract repeatedly.
Remember that your headlamps light up far less of a
roadway when you are in a turn or curve. Keep
your eyes moving; that way, it's easier to pick out dimly
lighted objects. Just as your headlamps should be
checked regularly for proper aim, so should your eyes
be examined regularly. Some drivers suffer from
night blindness Ð the inability to see in dim light Ð and
aren't even aware of it.
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Driving in Rain and on Wet Roads
Rain and wet roads can mean driving trouble. On a wet
road, you can't stop, accelerate or turn as well
because your tire-to-road traction isn't as good as on
dry roads. And, if your tires don't have much tread left,
you'll get even less traction. It's 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
re¯exes are tuned for driving on dry pavement.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's wise to keep your wiping equipment in good shape
and keep your windshield washer tank ®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.
4-30

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 can't, try to slow down before you
hit them.
{CAUTION:
Wet brakes can cause accidents. They won't
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.
Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen if the road is wet enough and
you're going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.Hydroplaning doesn't happen often. But it can if your
tires do not have much tread or if the pressure in one or
more is low. It can happen if a lot of water is standing
on the road. If you can see re¯ections from trees,
telephone poles or other vehicles, and raindrops
ªdimpleº the water's surface, there could be
hydroplaning.
Hydroplaning usually happens at higher speeds. There
just isn't a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
Driving Through Deep Standing Water
Notice:If you drive too quickly through deep
puddles or standing water, water can come in
through your engine's air intake and badly damage
your engine. Never drive through water that is
slightly lower than the underbody of your vehicle. If
you can't avoid deep puddles or standing water,
drive through them very slowly.
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Driving Through Flowing Water
{CAUTION:
Flowing or rushing water creates strong
forces. If you try to drive through ¯owing
water, as you might at a low water crossing,
your vehicle can be carried away. As little as
six inches of ¯owing water can carry away a
smaller vehicle. If this happens, you and other
vehicle occupants could drown. Don't ignore
police warning signs, and otherwise be very
cautious about trying to drive through ¯owing
water.
Some Other Rainy Weather Tips
·Besides slowing down, allow some extra following
distance. And be especially careful when you
pass another vehicle. Allow yourself more clear
room ahead, and be prepared to have your
view restricted by road spray.
·Have good tires with proper tread depth. SeeTires
on page 5-54
.
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City DrivingOne of the biggest problems with city streets is the
amount of traffic on them. You'll want to watch out for
what the other drivers are doing and pay attention
to traffic signals.
Here are ways to increase your safety in city driving:
·Know the best way to get to where you are
going. Get a city map and plan your trip into
an unknown part of the city just as you would for a
cross-country trip.
·Try to use the freeways that rim and crisscross
most large cities. You'll save time and energy.
See
Freeway Driving on page 4-34.
·Treat a green light as a warning signal. A traffic
light is there because the corner is busy enough
to need it. When a light turns green, and just before
you start to move, check both ways for vehicles
that have not cleared the intersection or may
be running the red light.
4-33

Freeway Driving
Mile for mile, freeways (also called thruways, parkways,
expressways, turnpikes or superhighways) are the
safest of all roads. But they have their own special rules.The most important advice on freeway driving is: Keep
up with traffic and keep to the right. Drive at the
same speed most of the other drivers are driving.
Too-fast or too-slow driving breaks a smooth traffic ¯ow.
Treat the left lane on a freeway as a passing lane.
At the entrance, there is usually a ramp that leads to
the freeway. If you have a clear view of the freeway as
you drive along the entrance ramp, you should begin
to check traffic. Try to determine where you expect
to blend with the ¯ow. Try to merge into the gap at close
to the prevailing speed. Switch on your turn signal,
check your mirrors and glance over your shoulder as
often as necessary. Try to blend smoothly with the
traffic ¯ow.
Once you are on the freeway, adjust your speed to the
posted limit or to the prevailing rate if it's slower.
Stay in the right lane unless you want to pass.
Before changing lanes, check your mirrors. Then use
your turn signal.
Just before you leave the lane, glance quickly over your
shoulder to make sure there isn't another vehicle in
your ªblindº spot.
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Once you are moving on the freeway, make certain you
allow a reasonable following distance. Expect to
move slightly slower at night.
When you want to leave the freeway, move to the
proper lane well in advance. If you miss your exit, do
not, under any circumstances, stop and back up. Drive
on to the next exit.
The exit ramp can be curved, sometimes quite sharply.
The exit speed is usually posted.
Reduce your speed according to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you may tend to think you are
going slower than you actually are.
Before Leaving on a Long Trip
Make sure you're ready. Try to be well rested. If you
must start when you're not fresh Ð such as after a day's
work Ð don't plan to make too many miles that ®rst
part of the journey. Wear comfortable clothing and shoes
you can easily drive in.Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it's ready to go. If it needs
service, have it done before starting out. Of course,
you'll ®nd experienced and able service experts in GM
dealerships all across North America. They'll be
ready and willing to help if you need it.
Here are some things you can check before a trip:
·Windshield Washer Fluid:Is the reservoir full? Are
all windows clean inside and outside?
·Wiper Blades:Are they in good shape?
·Fuel, Engine Oil, Other Fluids:Have you checked
all levels?
·Lamps:Are they all working? Are the lenses clean?
·Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough for
long-distance driving? Are the tires all in¯ated to the
recommended pressure?
·Weather Forecasts:What's the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
·Maps:Do you have up-to-date maps?
4-35

Highway Hypnosis
Is there actually such a condition as ªhighway
hypnosisº? Or is it just plain falling asleep at the wheel?
Call it highway hypnosis, lack of awareness, or
whatever.
There is something about an easy stretch of road with
the same scenery, along with the hum of the tires on the
road, the drone of the engine, and the rush of the
wind against the vehicle that can make you sleepy. Don't
let it happen to you! If it does, your vehicle can leave
the road in
less than a second,and you could crash and
be injured.What can you do about highway hypnosis? First, be
aware that it can happen.
Then here are some tips:
·Make sure your vehicle is well ventilated, with a
comfortably cool interior.
·Keep your eyes moving. Scan the road ahead and
to the sides. Check your mirrors and your
instruments frequently.
·If you get sleepy, pull off the road into a rest,
service or parking area and take a nap, get some
exercise, or both. For safety, treat drowsiness
on the highway as an emergency.
4-36