GMC Duramax Diesel 2015 Owner's Manual page 98

Caution
Using coolant other than
®
DEX-COOL can cause
premature engine, heater core,
or radiator corrosion. In addition,
the engine coolant could require
changing sooner. Any repairs
would not be covered by the
vehicle warranty. Always use
DEX-COOL (silicate-free) coolant
in the vehicle.
What to Use
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant which will not damage
aluminum parts. If using this
mixture, nothing else needs to be
added.
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 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 coolant.
If coolant has to be added more
than four times a year, have the
dealer check the vehicle cooling
system.
Vehicle Care
Caution
If improper coolant mixture,
inhibitors, or additives are used in
the vehicle cooling system, the
engine could overheat and be
damaged. Too much water in the
mixture can freeze and crack
engine cooling parts. The repairs
would not be covered by the
vehicle warranty. Use only the
proper mixture of engine coolant
for the cooling system. See
Recommended Fluids and
Lubricants on page 11-8.
Never dispose of engine coolant by
putting it in the trash, or by pouring
it on the ground, or pouring 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.
10-19