2003 Buick Rendezvous Owner's Manual - Page 333

Engine Coolant The cooling system 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 km), whichever occurs first, if you add only DEX-COOL@ extended life coolant. The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine overheating, see Engine Overheating on page 5-25. A 50/50 mixture of clean, drinkable water and DEX-COOL@ coolant will: Notice: When adding coolant, it is important that you 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. 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 is new vehicle than DEX-COOL@ not covered by your warranty. -- 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. 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 messages and gages work as they should. 5-22