1998 Oldsmobile Aurora Owner's Manual - Page 274

What to Use Use a mixture of one-half clean water (preferably distilled) and one-half DEX-COOL@coolant which won't damage aluminum parts. If you use this mixture, you don't need to add anything else. NOTICE: If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost wouldn't be covered your by 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 retailer check your cooling system. Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol, can boil before the proper coolant mixturewill. 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 wouldn't you get the overheat warning. Your engine could catch fire and or others could burned. you be Use a 50/50 mixture of clean water and DEX-COOL@coolant. NOTICE: ~~ ~ If you use the proper coolant, don't have to you add extra inhibitors or additives which claim to improve the system. These can be harmful. 6-22