1998 Cadillac DeVille Owner's Manual - Page 309

Engine Coolant The cooling s stem in your vehicle is filled with DEX-COOL engine coolant. This coolant is designed to remain in your vehicle for 5 years or 150,000 miles (240 000 k )whichever occurs first, if you add only m DEX-COOL' extended life coolant. B NOTICE: When adding coolant, is important that you it use onlyDEX-COOL@(silicate-free) coolant. If coolant other than DEX-COOL is added to the system, premature engine, heater core or radiator corrosion may result. addition, the In engine coolant willrequire 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. The following explains your cooling system and how to add coolant when is low. If you have a problem it with engine overheating,see "Engine Overheating" in the Index. -- A 50/50 mixture of water and DEX-COOL' coolant will: 0 Give freezing protection down to -34°F (-37°C). 0 Give boiling protection up 265 "F ( 129 C). to 0 Protect against rust and corrosion. 0 Help keep the proper engine temperature. 0 Let the warning lights and gages work as they should. O 6-22