1997 Chevrolet Tahoe Owner's Manual - Page 306

What to Use Use a mixture of one-half clean water (preferably distilled) and one-half DEX-COOLS coolant which won't damage aluminum parts. If you use this mixture, you don't need to add anything else. I NOTICE: If'you use an improper coolant mix,your engine could overheat and be badly damaged. The repair cost wouldn't be covered by yourwarranty. Too much water in themix can freezeand crack the engine, radiator, heater core and other parts. J A CAUTION: Adding onlyplain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol, boil before the proper can coolant mix will.Your vehicle's coolant warning system is set for the proper coolant mix. With plain .wateror the wrong mix,your engine could get too hot but you wouldn't getthe overheat warning. Your engine couldcatch fire and you or others could be burned. Use a 50/50 mix of clean water and DEX-COOL@coolant. If you have to add coolant more than four times a year, have your dealer check your cooling system. NOTICE: ~~ ~~ If you use the propercoolant, you don't have to add extra inhibitors additives which claim to or improve the system. These can be harmful. 6-27