GMC Chevrolet Tahoe 2003 Manual page 406

A 50/50 mixture of clean, drinkable water and
®
DEX-COOL coolant will:
Give freezing protection down to −34°F ( −37°C).
•
•
Give boiling protection up to 265°F (129°C).
•
Protect against rust and corrosion.
•
Help keep the proper engine temperature.
•
Let the warning lights and gages work as they
should.
Notice: When adding coolant, it is important that
you use only DEX-COOL
If coolant other than DEX-COOL
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner — at 30,000 miles
(50,000 km) or 24 months, whichever occurs first.
Damage caused by the use of coolant other
®
than DEX-COOL is not covered by your new vehicle
warranty.
5-30
®
(silicate-free) coolant.
®
is added to
What to Use
Use a mixture of one-half clean, drinkable water and
®
one-half DEX-COOL coolant which won't damage
aluminum parts. If you use this coolant mixture,
you don't need to add anything else.
{
CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle's coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch fire and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®
coolant.