Chevrolet 2003 Impala Owner's Manual page 287

Nofice: Engine damage from running your engine
without coolant isn't covered by your warranty.
See "Overheated Engine Protection Operating
Mode" in the Index for information on driving to a
safe place in an emergency.
Notice; When adding coolant, it is important that
you use only DEX-COOL@ (silicate-free) coolant.
If coolant other than DEX-COOL@ is added to
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.
How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at the COLD mark, add a 50/50 mixture of
clean,
drinkable water
and DEX-COOL@ engine coolant at
the coolant recovery tank. See
Engine Coolant on
page
5-26 for more information.
Adding only plain water to your coollllg
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 wouldn't 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.
5-34