The 2008 Chevy Impala uses Dexron VI automatic transmission fluid (ATF) in its automatic transmission.
The Impala from that year generally runs on the GM 4T65-E four-speed automatic transmission. GM’s service guidance for this setup specifies Dexron VI ATF as the preferred fluid. If Dexron VI isn’t available, Dexron III/Mercon can be used as a temporary substitute, but you should plan to switch to Dexron VI at the next service to maintain optimal shifting and longevity.
Key considerations and options for this model’s transmission fluid are below:
- Dexron VI ATF — GM’s current recommended fluid for the 4T65-E transmission used in the 2008 Impala. It delivers proper shifting, lubrication, and heat management for modern GM automatics.
- Dexron III/Mercon — Older formulations that may be acceptable as a temporary substitute if Dexron VI cannot be sourced immediately. This should not be considered a long-term replacement.
- Avoid mixing fluids — use a single compatible ATF type during a fill or drain-and-fill service to prevent shifting issues or fluid incompatibility.
In summary, Dexron VI ATF is the preferred choice for the 2008 Chevrolet Impala. Dexron III/Mercon can serve as a short-term stand-in if necessary, but plan a future fluid change to Dexron VI to ensure consistent performance and protection.
Summary
For a 2008 Chevy Impala, the recommended transmission oil is Dexron VI automatic transmission fluid. If Dexron VI isn’t available, Dexron III/Mercon may be used temporarily, but switching to Dexron VI is advised for ongoing reliability.