Pennzoil Automatic Transmission Fluid has been renamed as Pennzoil Dex/Merc ATF to highlight the applications covered. Designed to meet the stringent requirements of leading automotive transmission manufacturers, Pennzoil Dex/Merc ATF is a high quality automatic transmission fluid that provides consistent, reliable and smooth operation of transmission systems. It features a high oxidation resistance and shear stability, as well as dependable anti-wear and gear protection to help extend the life of transmission components.