1996 Cadillac DeVille Owner's Manual - Page 282

A CAUTION: Adding only plain water to yourcooling 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 forthe propercoolant mix. With plain water or the wrongmix, your enginecould get toohot but you wouldn't get the overheat warning. Your engine could catch fire andyou or others could be burned. Use a 50/50 mix of clean water andDEX-COOL (orange-colored, silicate-free) antifreeze. NOTICE: If you use an impropercoolant mix, your engine could overheat andbe badly damaged. The repair cost wouldn't be covered by your warranty. Too much waterin the mix can freeze and crack theengine, radiator, heatercore and other parts. [f you have to add coolant more than four times a year, lave your dealer check your cooling system. NOTICE: If you use the propercoolant, you don't haveto add extrainhibitors or additives which claimto improve the system. These can be harmful.