Abstract: A compound comprising i) 20-80 mol % of at least one monoethylenically unsaturated dicarboxylic acid or anhydride thereof, ii) 5-30 mol % of at least one unsaturated oligomer of an optionally branched olefin having 2 to 20 carbon atoms, having an average molecular weight Mw of 300-5000, iii) 10-60 mol % of an ethylenically unsaturated acid having at least 10 carbon atoms, or a mono-,di- or tri- ester of glycerol (1, 2, 3 propanetriol) in which at least one of the carboxylic acid residues of the ester is derived from said ethylenically unsaturated acid, or an oil, optionally hydrolysed, containing at least 30 wt % of the acid or ester is disclosed, which has both dispersant and VI improving properties in lubricating oils.

Abstract: An additive concentrate suitable for incorporation into a finished lubricating oil composition is disclosed. The additive concentrate comprises:(a) a lubricating oil, and(b) a lubricating oil soluble sulphurized or non-sulphurized alkaline earth metal hydrocarbyl phenate modified by incorporation from 2 to less than 40% by weight based on the weight of said concentrate of either (i) at least one carboxylic acid having the formula: ##STR1## wherein R is a C.sub.10 to C.sub.24 alkyl or alkenyl group and R.sup.1 is either hydrogen, a C.sub.1 to C.sub.4 alkyl group or a --CH.sub.2 --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, said concentrate having a TBN greater than 300, and a viscosity at 100.degree. C. of less than 1,000 cSt. A process for making the foregoing concentrate is disclosed.

Abstract: An additive concentrate suitable for incorporation into a finished lubricating oil composition is disclosed. The additive concentrate comprises: (a) a lubricating oil; (b) a lubricating oil soluble sulphurized 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), ##STR1## wherein R is C.sub.10 to C.sub.24 alkyl or alkenyl group and R.sup.1 is either hydrogen, a C.sub.1 to C.sub.4 alkyl group or a --CH.sub.2 --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. A process for making the foregoing additive concentrate is disclosed. A finished lubricating oil composition containing the foregoing additive concentrate is also disclosed.

Abstract: A lubricating oil composition suitable for use in a low or medium speed diesel engine comprising a fuel oil with a residual oil content is characterised in that the lubricating oil composition further comprises a hydrocarbyl substituted amine or polyamine. The effect of such an amine is to reduce deposits due to the residual oil. A method of reducing deposits in a low or medium speed diesel engine is also disclosed.