Very Cold Weather Operation - GMC 2003 GMT560 T-Series Owner's Manual

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.
It is acceptable to use diesel fuel containing up to 5%
biodiesel (B5), but the final blended fuel must meet
the same specification, CAN/CGSB—3.517–2000 (Low
Sulfur Diesel) in Canada, as other fuels used in your
vehicle, and the biodiesel used for making this fuel must
meet the ASTM D6751–02 specification. 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.

Very Cold Weather Operation

Follow the instructions listed previously under the
heading "What Fuel to Use."
Notice: Never use home heating oil or gasoline in
your diesel engine. They can cause engine
damage.
In cold weather, your fuel filter may become clogged
(waxed). To unclog it, move the vehicle to a warm
garage area and warm the filter to between 32°F and
50°F (0°C to 10°C). You won't need to replace it.
Additional information on the fuel filter follows.
5-7