Starting with the 2006 model year, General Motors is changing their automatic transmission fluid for all Hydra-Matic transmissions. The new fluid, on the market as DEXRON-VI, was developed in conjunction with Petro-Canada and Afton Chemical Corp. The ATF fluid has proven to deliver more than twice the durability and stability in friction test compared to existing fluids. The first factory application for the new ATF is the six-speed Hydra-Matic 6L80 that will be used in the Cadillac STS-V and XLR-V high performance variants. The new fluid has been approved for service on all prior year Hydra-Matic transmissions.