1993 Buick Roadmaster Owner's Manual - Page 259

er to yourcooling system can be dangerous. Plain water, some other or liquid like alcohol, canboil before the proper coolant mix will. Your vehicle's coolant warning system is set for the proper coolant mix. Wi'th 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 50/50 mix of clean water and a proper antifreeze. 257