Buick LaCrosse Owner's Manual page 354

The cooling system in the vehicle is
®
filled with DEX-COOL
coolant mixture. See
and
for more information.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see
.
engine
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 for
non-eAssist engine(s). Use a
50/50 mixture of deionized water
and DEX-COOL coolant for
eAssist engine(s).
Use a 50/50 mixture of deionized
water or 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.