
Diesel Engine Fuel
For the Caterpillar®diesel, see the Caterpillar®
Operation & Maintenance Manual for information
concerning fuel usage.
Notice:Diesel fuel or fuel additives not
recommended in this manual could damage your
fuel system and engine. Your warranty would
not cover this damage. And:
Diesel fuel that has been mixed with engine oil
or automatic transmission uid could damage
your engine and emission controls.
Aftermarket diesel fuel additives are not tested
by General Motors. Some additives, particularly
those which contain alcohol or water
emulsi ers, may damage your fuel system. If
you believe that unique circumstances call for a
fuel additive to be used, consult your dealer
for advice.
If you ever run out of diesel fuel, it can be
difficult to restart your engine. To avoid all this,
never let your tank get empty.
If you run out of fuel,Running Out of Fuel on page 5-15,
tells you how to restart your engine.
What Fuel to Use
In the United States, for best results use Number 2–D
diesel fuel year-round (above and below freezing
conditions) as oil companies blend Number 2–D fuel to
address climate differences. Number 1–D diesel fuel
may be used in very cold temperatures (when it
stays below 0°F or−18°C); however, it will produce a
power and fuel economy loss. Avoid the use of Number
1–D diesel fuel in warm or hot climates. It may result
in stalling, poor starting when the engine is hot and may
damage the fuel injection system.
At a minimum, the diesel fuel you use should meet
specifications ASTM D975-02 (Grade Low Sulfur) in the
United States. In addition, the Engine Manufacturers
Association (EMA) has identified properties of an
improved diesel fuel for better engine performance and
durability. Diesel fuels corresponding to the EMA
Recommended Guideline on Premium Diesel Fuel
(FQP-1A) could provide better starting, less noise and
better vehicle performance. If there are questions
about the fuel you are using, contact your fuel supplier.
It is acceptable to use diesel fuel containing up to
5% biodiesel (B5), but the final blended fuel must meet
the same specification, ASTM D975–02 (Grade Low
Sulfur), as other fuels used in your vehicle, and
the biodiesel used for making this fuel must meet the
ASTM D6751–02 specification.
5-8

Biodiesel is produced from vegetable oils or animal fat
that have been chemically modified to reduce the
possibility of damage to your fuel system and engine.
Higher concentration (i.e., greater than B5)
biodiesel-containing fuels or the use of unmodified
bio-oils blended into diesel fuel at any concentration is
not recommended and could damage your fuel
system and engine. Such damage would not be covered
by your warranty. If there are questions about the
biodiesel-containing fuels you are using, contact your
fuel supplier.
Diesel fuel may foam when you fill your tank. This can
cause the automatic pump nozzle to shut off, even
though your tank is not full. If this happens, just wait for
the foaming to stop and then continue to fill your tank.
{CAUTION:
Heat coming from the engine may cause the
fuel to expand and force the fuel out of your
tank. If something ignites the fuel, a re could
start and people could be burned. To help avoid
this, ll your fuel tank only until the automatic
nozzle shuts off. Do not try to “top it off.”
What Fuel to Use in Canada
Canadian fuels are blended for seasonal changes.
Diesel Type “A” fuel is blended for better cold weather
starting (below 0°F or−18°C); however, you may
notice some power and fuel economy loss. If Type “A”
fuel is used in warmer temperatures, stalling and
hard starting may occur. Diesel Type “B” fuel is blended
for temperatures above 0°F (−18°C). The emission
control system requires the use of diesel fuel with
low-sulfur (.05% by weight) content. Both low- and
higher-sulfur fuels will be available in Canada. Only
low-sulfur diesel fuels are available in the United States.
It is important that diesel-powered trucks are refueled
only with low-sulfur fuel. Use of fuels with higher-sulfur
content will affect the function of the emission
components and may cause reduced performance,
excessive smoke and unpleasant odor.
At a minimum, the diesel fuel you use should meet
specifications CAN/CGSB–3.517–2000 (Low Sulfur
Diesel) in Canada. In addition, the Engine Manufacturers
Association (EMA) has identified properties of an
improved diesel fuel for better engine performance and
durability (FQP-1A). Diesel fuels corresponding to
the EMA description could provide better starting, less
noise and better vehicle performance. If there are
questions about the fuel you are using, contact your fuel
supplier.
5-9

When you tilt the hood far enough, the cables will
support it.
When you close the hood, make sure both latches are
secured.
Engine Oil (Caterpillar®Diesel
Engine)
See your Caterpillar®Operation & Maintenance Manual
for information on oil quality and viscosities as well
as the temperature range chart.
Engine Oil (Gasoline Engine)
If the low oil light appears
on the instrument cluster, it
means you need to
check your engine oil level
right away. For more
information, seeLow Oil
Level Light on page 3-38.
You should check your engine oil level regularly; this is
an added reminder.
5-20

•SAE 5W-30
As shown in the viscosity chart, SAE 5W-30 is best
for your vehicle. However, if it is going to be 0°F
(−18°C) or above and SAE 5W-30 is not available,
you may use SAE 10W-30.
These numbers on an oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 20W-50.
Oils meeting these
requirements should also
have the starburst
symbol on the container.
This symbol indicates
that the oil has been
certified by the American
Petroleum Institute (API).
You should look for this information on the oil container,
and useonlythose oils that are identified as meeting
GM Standard GM6094M and have the starburst symbol
on the front of the oil container.Notice:Use only engine oil identi ed as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certi ed For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
®oil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the API service symbol are all you will need for
good performance and engine protection.
5-23

When to Change Engine Oil (GM Oil
Life System)
Your vehicle has a computer system that lets you know
when to change the engine oil and filter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated can
vary considerably. For the oil life system to work
properly, you must reset the system every time the oil is
changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A change engine oil light will come on.
Change your oil as soon as possible within the next two
times you stop for fuel. It is possible that, if you are
driving under the best conditions, the oil life system may
not indicate that an oil change is necessary for over a
year. However, your engine oil and filter must be
changed at least once a year and at this time the system
must be reset. Your dealer has GM-trained service
people who will perform this work using genuine GM
parts and reset the system. It is also important to check
your oil regularly and keep it at the proper level.
If the system is ever reset accidentally, you must change
your oil at 3,000 miles (5 000 km) since your last oil
change. Remember to reset the oil life system whenever
the oil is changed.
How to Reset the Change Engine Oil Light
The GM Oil Life System calculates when to change
your engine oil and filter based on vehicle use. Anytime
your oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change your oil prior to a
change engine oil light being turned on, reset the
system.
To reset the change engine oil light, do the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal slowly
three times within 10 seconds.
If the change engine oil light flashes for five
seconds, the system is resetting.
3. Turn the key to OFF.
If the change engine oil light comes back on when you
start your vehicle, the engine oil life system has not
reset. Repeat the procedure.
5-24

What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
filter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask
your dealer, a service station or a local recycling center
for help.
Engine Oil (DURAMAX™ Diesel)
Checking Engine Oil
It is a good idea to check your engine oil level every
time you get fuel.
The engine oil dipstick is
located in the engine
compartment on the
driver’s side of the vehicle.
In order to get an accurate reading, the oil must be
warm (at normal operating temperature) and the vehicle
must be on level ground.
5-25

What Kind of Engine Oil to Use
Look for these two things:
•CI-4 or CH-4
Oils designated as API CI-4 or CH-4 are
recommended for your vehicle. The CI-4 or CH-4
designations may appear either alone, together or in
combination with other API designations, such as
API CI-4/SL.
These letters show American Petroleum
Institute (API) levels of quality.
Notice:If you use oil that does not have this
designation, CH-4, you can cause engine damage
not covered by your warranty.
Notice:Use only engine oils that have one of these
designations CI-4 or CH-4 for the DURAMAX™ diesel
engine. Failure to use the recommended oils can
result in engine damage not covered by your
warranty.
•SAE 15W-40
As shown in the viscosity chart, SAE 15W-40 is
best for your vehicle. However, you can use
SAE 10W-30 at temperatures above 0°F (−18°C).
When it is very cold, below 0°F (−18°C), you should
use SAE 5W-40 to improve cold starting.
These numbers on the oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 10W-40 or SAE 20W-50.
This doughnut-shaped
logo (symbol) is used on
most oil containers to
help you select the correct
oil. It means that the oil
has been certified by
the American Petroleum
Institute.
You should look for this on the oil container, and use
onlythose oils that display this logo.
GM Goodwrench
®oil of the recommended viscosity
grades meets all the requirements for your vehicle.
5-28

The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-36.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F (−37°C).
•Give boiling protection up to 252°F (122°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant which won’t damage
aluminum parts. If you use this coolant mixture,
you don’t need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
5-33