1994 Pontiac Bonneville Owner's Manual - Page 215

Service & Appearance Care Engine Coolant (CONT.) What to Use Use a mixture of one-half clean water (preferably distilled) and one-half antifreeze that meets "GM Specification 1825-M," which won't damage aluminum parts. You can also use a recycled coolant conforming to GM Specification 1825-M with a complete coolant flush and refill. If you use this mixture, you don't need to add anything else. Adding Coolant To Check Coolant When your engine is cold, the coolant level should be at "FULL COLD" or a little higher. When your engine is warm, '.he level should be up to"FULL HOT" or 1 little higher. NOTICE: If you use an improper coolant mix, your engine could overheat and be badly damaged. The repair cost wouldn't be covered by your warranty. Too much water in the mix can freeze and crack the engine, radiator, heater core and other parts. ...214