GM DEX-COOL ORANGE 50/50 ANTIFREEZE / COOLANT- 1 GALLON. GM Dex-Cool Orange Antifreeze/Coolant 50/50 is a premium ethylene glycol based coolant engineered specifically for General Motors cooling systems that require Dex-Cool technology. Originally factory filled in many vehicles, Dex-Cool is used across brands such as Chevrolet, GMC, Buick, Cadillac, Pontiac, Saturn, and Hummer (1995+), along with Saab and Land Rover It is also authorized for most Ford (2011.