tires GMC SIERRA 2007 Owner's Guide

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 147for
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 the brake pedal
lightly until the 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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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 are going fast enough. When your
vehicle is hydroplaning, it has little or no contact
with the road.
Hydroplaning does not 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 reections from trees, telephone poles,
or other vehicles, and raindrops dimple the water’s
surface, there could be hydroplaning.
Hydroplaning usually happens at higher speeds.
There just is not 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 the engine’s air intake
and badly damage the engine. Never drive
through water that is slightly lower than the
underbody of your vehicle. If you cannot 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. Do not ignore
police warning signs, and otherwise be
very cautious about trying to drive
through owing water.
Some Other Rainy Weather Tips
Turn on your low-beam headlamps — not just
your parking lamps — to help make you more
visible to others.
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. See
Tires on page 550.
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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 inated to the recommended pressure?
Weather Forecasts:What is 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?
Highway Hypnosis
Is there actually such a condition as highway
hypnosis? 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. Do not 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 vehicle’s mirrors
and 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.
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Hill and Mountain Roads
Driving on steep hills or mountains is different
from driving in at or rolling terrain.If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that
can make your trips safer and more enjoyable. See
Off-Road Driving on page 390for information
about driving off-road.
Keep your vehicle in good shape. Check all
uid levels and also the brakes, tires,
cooling system, and transmission. These parts
can work hard on mountain roads.
{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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Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You may want to put winter emergency
supplies in your vehicle.
Also seeTires on page 550.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 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.
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 will have a lot less traction, or grip,
and will need to be very careful.
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You will need a well-charged battery to restart the
vehicle, and possibly for signaling later on with
your headlamps. Let the heater run for a while.
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
In order to free your vehicle when it is stuck, you
need to spin the wheels, but you do not want
to spin the wheels too fast. The method known as
rocking can help you get out when you are
stuck, but you must use caution.
{CAUTION:
If you let your vehicle’s tires spin at high
speed, they can explode, and you or
others could be injured. And, the
transmission or other parts of the vehicle
can overheat. That could cause an engine
compartment re or other damage. When
you are stuck, spin the wheels as little as
possible. Do not spin the wheels above
35 mph (55 km/h) as shown on the
speedometer.
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Notice:Spinning the wheels can destroy parts
of your vehicle as well as the tires. If you
spin the wheels too fast while shifting
the transmission back and forth, you can
destroy the transmission.
For information about using tire chains on your
vehicle, seeTire Chains on page 574.
Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right.
That will clear the area around the front wheels. If
you have a four-wheel-drive vehicle, shift into
Four-Wheel High. If your vehicle has StabiliTrak
®,
you should turn the system off. SeeStabiliTrak®
System on page 381. Then shift back and
forth between REVERSE (R) and a forward gear,
spinning the wheels as little as possible.Release the accelerator pedal while you shift, and
press lightly on the accelerator pedal when the
transmission is in gear. By slowly spinning
the wheels in the forward and reverse directions,
you will cause a rocking motion that may free
your vehicle. If that does not get your vehicle out
after a few tries, it may need to be towed out.
Or, you can use the recovery hooks if your vehicle
has them. If your vehicle does need to be towed
out, seeTowing Your Vehicle on page 439.
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The Tire and Loading Information label also shows
the size of the original equipment tires (C) and
the recommended cold tire ination pressures (D).
For more information on tires and ination see
Tires on page 550andInation - Tire Pressure on
page 559.
There is also important loading information on the
vehicle Certication/Tire label. It tells you the
Gross Vehicle Weight Rating (GVWR) and
the Gross Axle Weight Rating (GAWR) for the
front and rear axles. See “Certication/Tire Label”
later in this section.
Steps for Determining Correct Load Limit
1. Locate the statement “The combined
weight of occupants and cargo should never
exceed XXX kg or XXX lbs” on your
vehicle’s placard.
2. Determine the combined weight of the driver
and passengers that will be riding in your
vehicle.
3. Subtract the combined weight of the driver
and passengers from XXX kg or XXX lbs.4. The resulting gure equals the available
amount of cargo and luggage load capacity.
For example, if the “XXX” amount equals
1400 lbs and there will be ve 150 lb
passengers in your vehicle, the amount of
available cargo and luggage load capacity is
650 lbs (1400−750 (5 x 150) = 650 lbs).
5. Determine the combined weight of luggage
and cargo being loaded on the vehicle. That
weight may not safely exceed the available
cargo and luggage load capacity calculated in
Step 4.
6. If your vehicle will be towing a trailer, the load
from your trailer will be transferred to your
vehicle. Consult this manual to determine how
this reduces the available cargo and luggage
load capacity of your vehicle. SeeTowing
a Trailer on page 445for important information
on towing a trailer, towing safety rules and
trailering tips.
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Item Description Total
AVehicle Capacity Weight
for Example 3=1,000 lbs (453 kg)
BSubtract Occupant
Weight 200 lbs
(91 kg)×5=1000 lbs (453 kg)
C Available Cargo Weight=0 lbs (0 kg)
Refer to your vehicle’s tire and loading information
label for specic information about your vehicle’s
capacity weight and seating positions. The
combined weight of the driver, passengers, and
cargo should never exceed your vehicle’s capacity
weight.
Certication/Tire Label
A vehicle specic Certication/Tire label is found
on the rear edge of the driver’s door. The
label shows the size of your vehicle’s original tires
and the ination pressures needed to obtain the
gross weight capacity of your vehicle. This is called
Gross Vehicle Weight Rating (GVWR). The
GVWR includes the weight of the vehicle, all
occupants, fuel, and cargo.
The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR).
Example 3
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