The 2008 GMC Acadia uses Dex-Cool orange long-life coolant (an organic acid technology, or OAT, formulation).
GM-approved Dex-Cool or an equivalent OAT coolant meeting GM specifications is recommended. Do not mix Dex-Cool with conventional green coolant, and if you’re topping off, use the same type or consult the owner's manual or a GM service specialist for guidance.
Dex-Cool: GM's orange long-life coolant
Dex-Cool has been GM’s standard coolant for many vehicle lines since the late 1990s. The orange, OAT-based formula is designed to provide extended protection against corrosion and overheating, typically lasting up to about five years or 150,000 miles under normal driving conditions. Actual service intervals can vary based on climate and maintenance history.
Verifying coolant type in your Acadia
To confirm what coolant is currently in your system, check the coolant reservoir cap label or the service documentation. An orange Dex-Cool cap or label usually indicates Dex-Cool is being used. If the cap or label is green or the coolant has green tint, a conventional green coolant may be present. When in doubt, consult a dealer or qualified mechanic to prevent cross-contamination.
If you are shopping for coolant, keep these guidelines in mind:
- Use Dex-Cool or a coolant that meets GM Dex-Cool/OAT specifications (GM 6277M or equivalent) and is labeled accordingly.
- Avoid mixing Dex-Cool with conventional green coolant or other incompatible chemistries, which can cause sludge and degraded cooling efficiency.
- When filling or flushing, mix with distilled water to achieve the recommended 50/50 ratio unless climate or manufacturer guidance specifies otherwise.
- Always purge and replace the entire cooling system if changing coolant types; do not reuse old coolant from the system.
Following these guidelines helps maintain corrosion protection and reliable cooling system performance in the Acadia.
Summary
The 2008 GMC Acadia uses Dex-Cool orange long-life coolant (OAT). Use Dex-Cool or GM-approved OAT coolant, avoid mixing with green coolant, and follow proper mixing and replacement procedures to maintain cooling-system reliability. For any doubt, refer to the owner's manual or consult a GM service professional.