GMC Yukon XL Denali Owner's Manual page 333

What to Use
WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or
others could be burned. Use a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:
Gives freezing protection down
to 37°C ( 34°F), outside
temperature.
Gives boiling protection up to
129°C (265°F), engine
temperature.
Protects against rust and
corrosion.
Will not damage aluminum parts.
Helps keep the proper engine
temperature.
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.
Vehicle Care
Notice: If extra inhibitors and/or
additives are used in the vehicle
cooling system, the vehicle could
be damaged. Use only the proper
mixture of the engine coolant
listed in this manual for the
cooling system. See
Recommended Fluids and
Lubricants on page 11 12 for
more information.
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or into sewers, streams,
or bodies of water. Have the coolant
changed by an authorized service
center, familiar with legal
requirements regarding used
coolant disposal. This will help
protect the environment and your
health.
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
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