2003 Buick Century Owner's Manual - Page 239

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 coolant. life The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine overheating or if you need to add coolant to your radiator, see Engine Overheating on page 5-25. 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 onlyDEX-COOL@(silicate-free) coolant. If coolant other thanDEX-COOL@ added to is the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner at 30,000miles (50,000 km) or 24 months, whichever occurs first. Damage caused by the useof coolant other than DEX-COOL@ not covered by your new is vehicle 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. 5-22