1993 Pontiac Firebird Owner's Manual - Page 238

Engine Coolant The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine in overheating, see "Engine Overheating'' the Index. The proper coolantfor your Pontiac will: 0 Give freezing protection down to -34°F (-37°C). 0 Give boiling protection upto 262°F (128°C). Protect against rust and corrosion. Help keep the proper engine temperature. Let the warning lights work as they should. What to Use: Use a mixture of one-half clean water (preferably distilled) and one-half antifreeze that meets "GM Specification 1825M," which won'tdamage aluminum parts. You can also use a recycled coolant conforming to GM Specification 1825M with a complete coolant flush and refill. If you use this mixture, you don't need to add anythingelse. PAIITlnN= your cooling system can be dangerous. Plain water, or some other liquid like alcohol, can boil before the proper coolant mix will. Your vehicle's coolant warning system is set for the proper coolant mix. With plain water or the wrong mix, 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 SO/SO mix of clean water and a proper antifreeze. I 237 I 9