GMC Sierra Denali 2009 Owner's Manual page 368

What to Use
CAUTION:
{
Adding only plain water to the cooling system can
be dangerous. Plain water, or some other liquid
such as alcohol, can boil before the proper coolant
mixture will. The vehicle's 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
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 −34°F (−37°C),
•
outside temperature.
•
Gives boiling protection up to 265°F (129°C),
engine temperature.
5-28
•
•
•
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.
Notice: If extra inhibitors and/or additives are used
in the vehicle's 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
®
coolant.
Lubricants on page 6-13 for more information.
Protects against rust and corrosion.
Will not damage aluminum parts.
Helps keep the proper engine temperature.