| abstract |
ABSTRACT OF THE DISCLOSURE In accordance with the present invention, there are provided ashless heavy duty diesel lubricating oil compositions which comprise an oil of lubricating viscosity as the major component and as the minor component (A) at least 3 wt.% of at least one ashless dispersant, (B) at least 2 wt.% of at least one sulfurized alkyl phenol, and (C) at least 0.1 wt.% of at least one organo-sulfur compound of the formula wherein R4 and R5 are straight or branched chain alkyl, cyclic, alicyclic, aryl, alkylaryl or arylalkyl radicals having from 2 to about 30 carbon atoms, and w and z are numbers from 1 to about 8, wherein the lubricating oil is characterized by a total sulfated ash (SASH) level of less than 0.01 wt.%. |