1997 Pontiac Bonneville Owner's Manual - Page 278

NOTICE: When adding coolant, is important thatyou use it only DEX-COOL@(silicate-free) coolant. I coolant other than DEX-COOL@ is added to f the system, premature engine, heater core or In radiator corrosion may result. addition, the engine coolantwill require change sooner at 30,000 miles (50 000 km) or24 months, whichever occurs first. Damage caused by the use of coolant other than DEX-COOL@not is covered by your new vehicle warranty. Adding only plain water to your cooling system can be dangerous. Plain water, some other or liquid like alcohol, can boil before the proper coolant mixwill. Your vehicle's coolant warning system is set for the proper coolant With mix. plain water or the wrong your engine could mix, get toohot butyou wouldn't get the overheat warning. Your engine could catch fire and or you others could be burned. Use a 50/50 mix of clean water and DEX-COOL@ coolant. -- 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. 6-25