1997 Pontiac Sunfire Owner's Manual - Page 227

F CAUTION: Adding onlyplain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol, boil beforethe proper can coolant mix will, Your vehicle's coolant warning system isset for the proper coolant mix, With plain water or the wrong mix, your engine could get toohot but you wouldn't getthe overheat warning. Your engine could catch fire and you or others could beburned. Use a 50/50 mix of clean water and DEX-COOL@coolant. I NOTICE: ~~ In cold weather,water can freeze and crack the engine, radiator, heater core and other parts. So use the recommended coolant. You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engine parts are hot enough. Don't spill coolant on a hot engine.