Castrol Dextron 3 Automatic Transmission Fluid is and automatic transmission fluid and power steering fluid for use in GM automatic transmissions pre 2005 and in many automatic transmissions where DEXRON (II or III) or MERCON performance is required. It is also suitable for many earlier model Japanese vehicles where DEXRON type fluids are recommended. It is recommended for other transmissions where DEXRON and DEXRON II fluids are specified except Mercedes-Benz, ZF, BMW, Voith and Renk.