IMPROVED LUBRICANT PERFORMANCE FROM ADDITIVE-TREATED FUELS
A fuel composition improves the antiwear and viscosity controlling properties of an internal combustion engine lubricating oil during operation of the engine. Small amounts of the fuel composition combine with the engine lubricating oil during engine operation and this provides an antioxidant boost to the lubricating oil. Preferably the fuel contains at least 57 g/1000 1 (20 lbs/1000 barrels) of a substituted dicyclic aromatic amine which is free of benzylic hydrogen atoms such as a mono- and/or di- alpha -methyl styrene alkylated phenylenediamine and/or a hindered phenol such as a monostyreneated mono-isobuteneated cresol or di C16 alkyl phenol. A synergistic effect is demonstrated by a mixture of the aromatic amine and hindered phenol. The fuels used in the composition include gasolines and diesel fuels.