Abstract: A lubricating oil composition having a total base number of more than 15 mg KOH/g including oil of lubricating viscosity; detergent; and at least one compound of the formula (I) and/or formula (II): wherein Ar and Ar? represent substituted or unsubstituted aromatic moieties; L and L? are linking moieties; each Y is independently —ORI?or H(O(CR12)n)yX—, wherein X is (CR1?2)z, O or S; R1 and R1? are H, alkyl or aryl; R1? is alkyl or aryl; each Y? is independently Z(O(CR22)n?)y?X?—, wherein X? is (CR2?2)z?, O or S; R2 and R2? are H, alkyl or aryl; Z is H, acyl, alkyl or aryl; z and z? are 1 to 10; n is 0 to 10 when X is (CR1?2)z and 2 to 10 when X is O or S; n? is 0 to 10 when X? is (CR2?2)z?, and 2 to 10 when X? is O or S; y and y? are 1 to 30; a and a? are 0 to 3; and m and m? are 1 to 100, with the proviso that in compounds of formula (I), at least one Ar moiety bears at least one group Y and that in compounds of formula (II), at least one Ar? moiety bears at least one group Y? in wherein Z is not H.

Abstract: A lubricating oil composition having a total base number of more than 15 mg KOH/g, as determined by ASTM D2896, and including at least 40 mass % of an oil of lubricating viscosity; at least one detergent; and at least one compound of the formula (I) and/or formula (II): In formula (I), each Ar independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, aryloxy, aryloxyalkyl, hydroxy, hydroxyalkyl, halo and combinations thereof; each L is independently a linking moiety comprising a carbon-carbon single bond or a linking group; each Y is independently —OR1? or a moiety of the formula H(O(CR12)n)yX—, wherein X is selected from the group consisting of (CR1?2)z, O and S; R1 and R1? are each independently selected from H, C1 to C6 alkyl and aryl; R1? is selected from C1 to C100 alkyl and aryl; z is 1 to 10; n is 0 to 10 when X is (CR1?2)z, and 2 to 10 when X is O or S; and y is 1 to 30; each a is independently 0 to 3, with the proviso