GMC 1994 Yukon Owner's Manual page 252

What Fuel to Use
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. Numer 1-D diesel fuel may be used in below freezing
weather, however, it will produce a power and fuel economy loss. The use
of number 1-D diesel fuel in warm or hot climates may result in stalling,
poor starting when the engine is hot and may damage the fuel injection
system.
Diesel fuel may foam when you fill your tank. This can cause the automatic
pump nozzle to shut off, even though your tank isn't full. If this happens,
just wait for the foaming to stop and then continue to fill your tank.
A
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
fire could start and people could be burned. To help avoid this,
fill your fuel tank only until the automatic nozzle shuts off.
Don't try to "top it off."
Cold Weather Operation
In cold weather (below 20"F, or -7"C), use 1-D or "Winterized" Number
2-D fuel (a blend of 1-D and 2-D). Be sure you get the right fuel. In very
cold temperatures (when it stays below 0°F or -18"C), use Number 1-D.
If you're driving in very cold temperatures and can't get Number 1-D or a
"winterized" Number 2-D, you can use one gallon of kerosene for every
two gallons of diesel fuel. Once you add the kerosene, run your engine for
several minutes so the fuels will mix. Add kerosene only when the
temperature falls below 0°F (-1 8" C ) , because the fuel economy of kerosene
isn't as good as that of diesel fuel.
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), especially if
you use Number 2-D diesel fuel that hasn't been "winterized." To unclog it,
warm the filter
to
between 32°F and 50°F (0°C to 10°C). You won't need
to replace
it.
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