The power steering fluid required for the 2007 Buick LaCrosse is Dexron VI automatic transmission fluid (ATF).
GM designed the LaCrosse’s hydraulic power steering system to operate with Dexron VI ATF, and Dexron VI is backward-compatible with older Dexron II/III fluids. For best results and seal longevity, use Dexron VI ATF or a GM-approved power steering fluid labeled Dexron VI. If Dexron VI isn’t available, Dexron II/III ATF can serve as a temporary substitute, but plan to switch to Dexron VI at the next service and consult the owner’s manual or a Buick service advisor for specifics on your vehicle.
Fluid choices and compatibility
Before refilling, consider these fluid options for the LaCrosse power steering system:
- Dexron VI automatic transmission fluid (ATF) — the recommended and preferred fluid for this system.
- Dexron II or Dexron III ATF — backward-compatible option if Dexron VI is not available; Dexron VI is preferred for ongoing use.
Bottom line: Dexron VI ATF is the best long-term choice; Dexron II/III ATF can be used temporarily if necessary, but upgrading to Dexron VI is advisable to maintain optimal steering performance and seal life.
Sources and best practices
Where to source the correct fluid and how to approach a refill or flush:
Look for Dexron VI ATF labeled for GM vehicles at automotive retailers, or use OEM-approved variants from trusted brands that specify Dexron VI compatibility. If switching from an older Dexron II/III fluid, consider flushing the system to prevent mixing and ensure proper performance, following the vehicle’s service manual guidance.
Summary
For a 2007 Buick LaCrosse, Dexron VI automatic transmission fluid is the recommended power steering fluid. Dexron VI is preferred and broadly compatible with older Dexron II/III fluids, which can be used temporarily if necessary. Always verify the exact specification in the owner's manual or with a Buick service professional, especially if the vehicle has a high mileage or a history of fluid changes.