Abstract: An internal-combustion engine lubricating oil composition has a P content of not greater than 0.09 mass %; a S content of not greater than 0.3 mass %; and a sulphated ash content of not greater than 1 mass %. It contains the following additives: as sole ashless, nitrogen-containing dispersant, and providing from 0.03 to 0.07 mass % of nitrogen in the lubricating oil composition, at least one ashless, nitrogen-containing derivative of a polyalkenyl-substituted mono- or dicarboxylic acid, anhydride or ester, the polyalkenyl-substituted mono- or dicarboxylic acid, anhydride or ester being made from a polyalkene exclusively by the thermal “ene” reaction; as sole overbased metal detergent, at least one overbased alkaline earth metal sulfonate; and at least one viscosity modifier.

Abstract: A lubricating oil composition for a heavy duty diesel engine comprises a base oil, at least 0.6 mass % of an ash-free antioxidant and an overbased magnesium-containing detergent. The detergent provides greater than 0.05 mass % Mg based on the mass of the composition. Bore polishing in the engine is reduced for a given level of exhaust gas ash production.

Abstract: A process for forming an ene reaction product wherein an enophile, such as maleic anhydride, is reacted with reactive polyalkene having a terminal vinylidene content of at least 30 mol. %, at high temperature in the presence of a free radical inhibitor. The polyalkenyl acylating agents are useful per se as additives in lubricating oils, functional fluids, and fuels and also serve as intermediates in the preparation of other products (e.g., succinimides) useful as additives in lubricating oils, functional fluids, and fuels. The presence of the free radical inhibitor during the high temperature reaction results in a reaction product that is low, or substantially free from sediment.

Abstract: An internal-combustion engine lubricating oil composition has a P content of not greater than 0.09 mass %; a S content of not greater than 0.3 mass %; and a sulphated ash content of not greater than 1 mass %. It contains the following additives: as sole ashless, nitrogen-containing dispersant, and providing from 0.03 to 0.07 mass % of nitrogen in the lubricating oil composition, at least one ashless, nitrogen-containing derivative of a polyalkenyl-substituted mono- or dicarboxylic acid, anhydride or ester, the polyalkenyl-substituted mono- or dicarboxylic acid, anhydride or ester being made from a polyalkene exclusively by the thermal “ene” reaction; as sole overbased metal detergent, at least one overbased alkaline earth metal sulfonate; and at least one viscosity modifier.

Abstract: A lubricating oil composition for a heavy duty diesel engine comprises a base oil, at least 0.6 mass % of an ash-free antioxidant and an overbased magnesium-containing detergent. The detergent provides greater than 0.05 mass % Mg based on the mass of the composition. Bore polishing in the engine is reduced for a given level of exhaust gas ash production.

Abstract: A process for forming an ene reaction product wherein an enophile, such as maleic anhydride, is reacted with reactive polyalkene having a terminal vinylidene content of at least 30 mol. %, at high temperature in the presence of a free radical inhibitor. The polyalkenyl acylating agents are useful per se as additives in lubricating oils, functional fluids, and fuels and also serve as intermediates in the preparation of other products (e.g., succinimides) useful as additives in lubricating oils, functional fluids, and fuels. The presence of the free radical inhibitor during the high temperature reaction results in a reaction product that is low, or substantially free from sediment.

Abstract: The reaction product of (i) an oligomer formed from one monomer or two or more different monomers, the or each monomer being an ethylenically unsaturated compound and said oligomer or each of said monomers being optionally partially or fully esterified, with (ii) a polyalkenyl derivative of an ethylenically unsaturated carboxylic reagent (iii), and (iv) a polyamine containing at least two --NH.sub.2 and/or --NH groups, wherein at least one of the ethylenically unsaturated compounds of the oligomer has a functional group which can react with an amine; and the use of the reaction product for its dispercency and low haze properties in lubricant compositions, fuel compositions and additive concentrates.

Abstract: The invention provides reaction products of:(A) an acylating reagent, with(D) a polyalkenyl derivative of an ethylenically unsaturated carboxylic reagent (C), and(E) a polyamine containing at least two --NH.sub.2 and/or --NH groups, or with(F) the pre-formed product of reagents (D) and (E), wherein the acylating reagent (A) is the reaction product of(B) a C.sub.4 -C.sub.20 polyene or oligomer prepared therefrom, and(C) an ethylenically unsaturated carboxylic reagent; lubricating oil compositions, fuel compositions and additive concentrates containing them; and use of the reaction products as dispersant additives.