The frictional characteristics of an automatic transmission fluid are an important factor in the design and operation of the transmission. All Ford transmissions built prior to 1977, and certain models that continued in use during 1977-1980, were designed for a high-friction fluid that allowed the shifting clutches to lock up or engage quickly. Ford specification ESW-M2C33-F covers this type of product, which is commonly referred to as "Type F" fluid. Mobil ATF Type F is the appropriate product for these units. These vehicles are identified as: All 1976 and earlier Ford, Lincoln, and Mercury models of cars, vans, and light trucks; All 1977-1980 models having either ESW-M2C33-F or no number at all stamped on the transmission dipstick. Mobil ATF Type F is also recommended for automatic transmissions in certain older Toyota, Mazda, Volvo, and other imported vehicles that require an ESW-M2C33-F fluid. In addition, this type of ATF is specified for some Ford power steering systems. Mobil ATF Type F is recommended for both makeup and refill in power steering systems of the following Ford vehicles: 1980 and older Lincoln, Continental, and Mark; 1978 and older models of all other Ford cars, vans, and light trucks. Mobil ATF Type F meets the anti-wear requirements of Sperry Vickers industrial hydraulic systems where low wear in the ASTM D 2882 vane pump test is the principal criterion. Mobil ATF Type F is not recommended for automatic transmissions in Ford, General Motors, Chrysler, American Motors, or any other cars requiring a Dexron-II, Dexron-IIE, Dexron-III or Mercon-approved fluid, or for those Ford products requiring an M2C138CJ (Type CJ) fluid or an M2C166H (Type H) fluid. For the above applications, Mobil Multi-Purpose ATF (Dexron/Mercon) is recommended.