| abstract |
An additive concentrate suitable for incorporation into a into a finished lubricating oil composition, the additive concentrate comprising: (a) a lubricating oil; (b) a lubricating oil soluble sulphurised alkaline earth metal hydrocarbyl phenate modified by incorporation of from greater than 2 to 35% by weight based on the weight of the composition of either (i) at least one carboxylic acid having formula (I), wherein R is C10 to C24 alkyl or alkenyl group and R1 is either hydrogen, a C1 to C4 alkyl group or a -CH2-COOH group, or an anhydride, acid chloride or ester thereof or (ii) a di- or polycarboxylic acid containing from 36 to 100 carbon atoms or an anhydride, acid chloride or ester thereof, the composition having a TBN greater than 300. |