2002 Chevrolet Prizm Owner's Manual - Page 207

How to Add Coolant to the Coolant Recovery Tank If you haven't found a problem yet, but the coolant level isn't at the FULL mark, add a 50/50 mixture of clean, drinkable water and a proper coolant at the coolant recovery tank. See "Engine Coolant" in the Index for more information about the proper coolant mixture. NOTICE: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant and the proper coolant mixture. CAUTION: Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid such as alcohol, can boil 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 get the overheat warning. Your engine could catch fire and you or others could be burned. Use a 50/50 mixture of clean, drinkable water and a proper coolant. 5-14