1994 Oldsmobile Achieva Owner's Manual - Page 189

What to Use Use amixture 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. 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. Adding Coolant To Check Coolant When your engine is cold, the coolant level should be at FULL COLD. To Add Coolant If you needmore coolant, add the proper mix at the surgetank, but only when the engine is cool. 187