1996 GMC Sonoma Owner's Manual - Page 247

A 50/50 mixture of water and the proper coolant for your vehicle will: 0 Give freezing protection down to -34°F (-37°C). Give boiling protection up to 265 "F ( 129°C). Protect against rust and corrosion. Help keep the proper engine temperature. Let the warning lights and gages work as they should. Use a mixture of one-half clear? ~vuter (preferably distilled) and one-half DEX-COOL (orange-colored, silicate-free) antifreeze that meets GM Specification 6277M, which won't damage aluminum parts. Use GM Engine Coolant Supplement (sealer) (GM Part No. 3634621) with any complete coolant change. If you use this mixture, you don't need to add anything else. TM NOTICE: When adding coolant it important thatyou use is DEX-COOL TM (orange-colored, silicate-free) coolant meetingGM Specification 6277M. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner at 30,000 miles (50 000 km) or24 months whichever occurs first. . A dding only plain water to your cooling 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 mix. With system is set for the proper coolant plain water or the wrong your engine could mix, get too hot butyou wouldn't get the overheat warning. Your engine could catch fire and or you others could be burned. a 50/50 mix of clean Use water and DEX-COOL (orange-colored, silicate-free) antifreeze. TM --