The 2020 GMC Sierra 5.3L V8 uses Dex-Cool Extended Life Antifreeze/Coolant (orange), GM’s organic acid technology coolant, typically supplied as a 50/50 premixed solution with distilled water.
Coolant type and specification
GM vehicles equipped with the 5.3L V8 generally require Dex-Cool coolant that meets GM’s Dex-Cool specification. The Sierra’s cooling system is designed for the orange, Extended Life version, and you can buy it as premixed 50/50 or as concentrate you mix to 50/50 with distilled water. Avoid mixing Dex-Cool with non-Dex-Cool or with green/silicate-based coolants to prevent deposits and potential cooling issues.
- Dex-Cool Extended Life Antifreeze/Coolant, orange, meeting GM Dex-Cool specification
- Dex-Cool concentrate, diluted with distilled water to a 50/50 ratio (if your service requires concentrate)
When in doubt, opt for the premixed 50/50 Dex-Cool to ensure the correct ratio and avoid improper mixing. Do not mix with incompatible coolants.
Maintenance and replacement intervals
GM generally recommends replacing Dex-Cool coolant every 5 years or 150,000 miles under normal driving conditions. In severe service, shorter intervals may apply. Always use the same Dex-Cool specification to maintain proper protection and prevent deposits.
For the exact interval and product details, consult the Sierra’s owner’s manual or contact a GM dealership or certified mechanic.
Identifying Dex-Cool in your vehicle
Dex-Cool is the orange/or amber coolant used by GM. If you’re topping off or performing a flush, confirm the product matches the Dex-Cool specification and avoid mixing with other coolant types.
Summary
Bottom line: Use Dex-Cool orange Extended Life coolant that meets GM specifications, typically as a 50/50 premixed solution. Follow GM’s maintenance intervals and avoid mixing with non-Dex-Cool coolants to keep the cooling system functioning properly.