2000 CHEVROLET SUBURBAN fuel

4-19 Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance and
service work done. Check to make sure all underbody
shields (if so equipped) are properly attached. Be sure
you read all the information about your four
-wheel-drive
vehicle in this manual. Is there enough fuel? Is the spare
tire fully inflated? Are the fluid levels up where they
should be? What are the local laws that apply to
off
-roading where you'll be driving? If you don't know,
you should check with law enforcement people in the
area. Will you be on someone's private land? If so,
be sure to get the necessary permission.
Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.

The heaviest things should be on the load floor and
forward of your 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 doesn't toss things around.
CAUTION:

Cargo on the load floor 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 floor can be
tossed about when driving over rough terrain.
You or your passengers can be struck by flying
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.
You'll find other important information in this manual.
See ªVehicle Loading,º ªLuggage Carrierº and ªTiresº
in the Index.

4-30
If the water isn't too deep, then drive through it slowly.
At fast speeds, water splashes on your ignition system
and your vehicle can stall. Stalling can also occur if you
get your tailpipe under water. And, as long as your
tailpipe is under water, you'll never be able to start your
engine. When you go through water, remember that
when your 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's
only shallow water, it can still wash away the
ground from under your tires, and you could lose
traction and roll the vehicle over. Don't drive
through rushing water.
See ªDriving Through Waterº in the Index for more
information on driving through water.
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 fire 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.

4-37
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
-- such as after a
day's work
-- don't plan to make too many miles that
first 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 find 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 inflated 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?

4-43
CAUTION:
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside. CO could overcome you and kill
you. You can't see it or smell it, so you might not
know it is in your vehicle. Clear away snow from
around the base of your vehicle, especially any
that is blocking your exhaust pipe. And check
around again from time to time to be sure snow
doesn't collect there.
Open a window just a little on the side of the
vehicle that's away from the wind. This will help
keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little faster
than just idle. That is, push the accelerator slightly.
This uses less fuel for the heat that you get and it
keeps the battery charged. 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.

4-46
Loading Your Vehicle
The Certification/Tire label is found on the rear edge of
the driver's door or in the Incomplete Vehicle Document
in the cab.The label shows the size of your original tires and the
inflation pressures needed to obtain the gross weight
capacity of your vehicle. This is called the GVWR
(Gross Vehicle Weight Rating). The GVWR includes
the weight of the vehicle, all occupants, fuel and cargo.
The Certification/Tire label also tells you the maximum
weights for the front and rear axles, called Gross Axle
Weight Rating (GAWR). To find out the actual loads
on your front and rear axles, you need to go to a weigh
station and weigh your vehicle. Your dealer can help
you with this. Be sure to spread out your load equally
on both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
The Certification/Tire label also contains information
about your Front Axle Reserve Capacity. See ªFront
Axle Reserve Capacityº later in this section.
And, if you do have a heavy load, you should spread
it out.

4-49 Front Axle Reserve Capacity
This is the difference between your front GAWR and
the front axle weight of your truck with full fuel and
passengers. It is the amount of weight you can add to
your front axle before reaching your front GAWR.
The front axle reserve
capacity for your vehicle
can be found in the lower
right hand corner of the
tire/certification label, as
shown in this example.
In order to calculate the amount of weight any
front accessory is adding to the front axle, use the
following formula.
(W x (A+W.B.)) / W.B.= Weight the accessory is adding
to the front axle
Where: W= Weight of added accessory
A= Distance that the accessory is
in front of the front axle
W.B.= Vehicle Wheelbase

4-50
For example, adding a 700 lb. ( 318 kg) snow plow
adds more than 700 lb. ( 318 kg) to the front axle.
Using the formula, if the snow plow is 4 ft. (122 cm)
in front of the front axle and the wheel base is
10 ft. (305 cm), then:
W= 700 lb. ( 318 kg), A= 4 ft. (122 cm) and
W.B.= 10 ft. (305 cm)
(W x (A+W.B.)) / W.B. = (700 x (4ft. + 10 ft.)) /
10 ft. = 980 lbs.
So, if your truck's front axle reserve capacity is more
than 980 lbs. (445 kg), you could add this snow plow
without exceeding the front GAWR.
You can add heavier equipment on the front of the
vehicle if you compensate for it by carrying fewer
passengers, less cargo or by positioning cargo more
towards the rear. This has the effect of reducing the
load on the front. However, the front GAWR, rear
GAWR and the GVWR must never be exceeded.Total Vehicle Reserve Capacity
This is the difference between your GVWR and the
weight of your truck with full fuel and passengers.
It is the amount of weight you can add to your vehicle
before reaching your GVWR.
The reserve capacity numbers are intended as a guide
when selecting the amount of equipment or cargo your
truck can carry. If you are unsure of your truck's front,
rear or total weight, go to a weigh station and weigh
your vehicle. Your dealer can help you with this.
Trailer Recommendations
You must subtract your hitch loads from the CWR
for your vehicle. Weigh your vehicle with the trailer
attached, so that you won't go over the GVWR or
GAWR. If you are using a weight
-distributing hitch,
weigh the vehicle without the equalizer bars in place.
You'll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information, see ªTrailer Towingº in the Index.

4-51
Towing a Trailer
CAUTION:
If you don't use the correct equipment and drive
properly, you can lose control when you pull a
trailer. For example, if the trailer is too heavy,
the brakes may not work well
-- or even at all.
You and your passengers could be seriously
injured. Pull a trailer only if you have followed
all the steps in this section. Ask your dealer for
advice and information about towing a trailer
with your vehicle.
NOTICE:
Pulling a trailer improperly can damage your
vehicle and result in costly repairs not covered by
your warranty. To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer
with your vehicle.
To identify what the vehicle trailering capacity is
for your vehicle, you should read the information
in ªWeight of the Trailerº that appears later in
this section.
If yours was built with trailering options, as many are,
it's ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.
That's the reason for this part. In it are many
time
-tested, important trailering tips and safety rules.
Many of these are important for your safety and that of
your passengers. So please read this section carefully
before you pull a trailer.