The Cadillac CTS generally uses Dexron VI automatic transmission fluid, with Dexron III historically specified for the earliest models. Exact requirements depend on the model year and the transmission type, so the owner’s manual or GM’s service information should be consulted for your specific car.
Gen 1 CTS (2003–2007): Transmission fluid type
Early CTS models used GM’s traditional 4-speed automatic transmission family. Here’s how the fluid guidance works for these years:
- Original specification: Dexron III. This was the standard fluid during the era.
- Replacement option: Dexron VI is broadly compatible and commonly used as a modern replacement, offering improved lubrication and protection.
Bottom line for Gen 1: Dexron III was the factory spec, but Dexron VI is a widely accepted replacement in many vehicles of this era.
Gen 2 CTS (2008–2013): Transmission fluid type
These models typically use a 6-speed automatic transmission (6L50/6L80 family). The fluid specification is more clearly aligned with newer GM standards.
- Recommended specification: Dexron VI.
- Compatibility note: Dexron III fluids can be used in a pinch, but Dexron VI is preferred for better performance, shift quality, and wear protection.
Bottom line for Gen 2: Dexron VI is the recommended fluid for these transmissions, with Dexron III as an acceptable older alternative.
Gen 3 CTS (2014–2019): Transmission fluid type
Final-generation CTS models predominantly use the 8-speed automatic (8L90). GM standardized on Dexron VI for these transmissions.
- Recommended specification: Dexron VI.
- Notes: Dexron VI provides the current standard for shifting performance and longevity; always verify exact requirements in your manual or GM Service Information.
Bottom line for Gen 3: Dexron VI is the primary and recommended fluid for these transmissions.
Summary
Across Cadillac CTS generations, Dexron VI has become the standard transmission fluid for newer models, while early CTS (2003–2007) originally called for Dexron III. Dexron VI is generally backward compatible and is widely used as the replacement fluid. Always confirm the exact specification for your year and transmission in the owner’s manual or GM’s official service information, and follow the recommended service intervals for fluid changes.