Oil compositions having improved fuel economy employing a synergistic combination of organomolybdenum components and methods for their use

摘要

An engine oil having a base oil and a friction reducing amount of an oil soluble sulfurized or unsulfurized oxymolybdenum complex prepared from reacting, in the presence of a polar promoter, an acidic molybdenum compound and a basic nitrogen compound and a low concentration of a sulfurized oxymolybdenum dialkyldithiocarbamate; employed together to provide at least 450 parts per million of molybdenum and less than 175 parts per million of molybdenum from the dialkyldithiocarbamate, both on the basis of the engine oil.