2003 Oldsmobile Alero Owner's Manual - Page 239

Notice: When adding coolant, it is important that (silicate-free) coolant. you use onlyDEX-COOL@ 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 soonerat 30,000miles (50,000 km) or 24 months, whichever occurs first. Damage caused by the use of coolant other than DEX-COOL@ not covered by your new vehicle is warranty. -- What to Use Use a mixture of one-half clean, drinkable wafer and coolant which won't damage one-half DEX-COOL@ aluminum parts. If you use this coolant mixture, you don't need to add anything else. Adding only plain water to your cooling system can be dangerous. Plainwater, or can boil some other liquid such as alcohol, 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 getthe 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. Notice: If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost wouldn't be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator,heater core and other parts. If you have to add coolant more than four times a year, have your dealer check your cooling system. Notice: If you use the proper coolant, you don't have to add extra inhibitors or additives which claim to improve the system.These can be harmful. 5-24