1997 Oldsmobile Cutlass Supreme Owner's Manual - Page 204

I NOTICE: I Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol, can boil before proper the coolant mix will. Your vehicle's coolant warning system is set for the proper coolant mix. With plain wateror the wrongmix, 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 mix of clean water and DEX-COOL coolant. TM In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. So use the recommended coolant. c You can beburned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engineparts arehot enough. Don't spill coolant on a hot engine.