The disclosed technology provides a method of lubricating a compression-ignition internal combustion engine with a maximum laden mass over 2,700 kg comprising supplying to the engine a lubricating composition comprising: an oil of lubricating viscosity, a 300 TBN or higher alkaline earth metal sulfonate detergent having a metal ratio of 10 to 40, an alkaline earth metal sulfonate detergent having a metal ratio of 3 to 9, and a TBN of 81 to 180 mg KOH/g, wherein the sulfonate detergents provide a total amount of sulfonate substrate of 1 wt % to 3 wt % of the lubricating composition, 0.1 to 1.2 wt % of antioxidant, wherein at least 20 wt % of the antioxidant is a phenolic antioxidant, a borated compound present in an amount to deliver 25 ppm to 300 ppm of boron, the lubricating composition has a sulfated ash content of 0.5 wt % to not more than 1.5 wt %, and the lubricating composition has a TBN of 6.5 to 15 mg KOH/g.

A lubricating oil composition comprising greater than 50 wt. % of a base oil of lubricating viscosity, and either: a) an additive composition comprising: one or more zinc dialkyl dithiophosphates (ZDDP compounds) and one or more dispersants, wherein the amount of zinc (Zn) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds multiplied by the contribution of the total base number (TBN) of the one or more dispersants to the TBN of the lubricating oil composition is a multiplication factor Zn*TBNDisp of at least about 0.06; or b) an additive composition comprising: one or more zinc dialkyl dithiophosphates (ZDDP compounds) and one or more dispersants, wherein the amount of phosphorus (P) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds multiplied by the contribution of the total base number (TBN) of the one or more dispersants to the TBN of the lubricating oil composition is a multiplication factor P*TBNDisp of at least about 0.051.

The present disclosure relates to lubricant additives such as dispersants and dispersant viscosity modifiers including acyl peptide grafted polymers and lubricating oil compositions comprising such additives. The disclosure also relates to the use of lubricant compositions comprising the additives herein for improving the soot or sludge handling characteristics of an engine lubricant composition and while minimizing the deterioration of engine's elastomer compatibility.

The present invention is directed to a use of a lubricant in a diesel engine to disperse soot produced by the diesel engine, the soot being dispersed without adversely affecting the viscosity of the lubricant; the lubricant comprising a major amount of oil of lubricating viscosity and a minor amount of a dispersant comprising (i) one or more olefin, (ii) one or more carboxylic acid, (iii) one or more polyetheramines and (iv) one or more aromatic amines along with co-additives.

The present disclosure relates to oxazoline modified lubricant additives that have dispersant properties and lubricating oil compositions comprising said dispersant lubricant additives. The disclosure also relates to the use of lubricant compositions comprising the additives of the disclosure for improving the soot or sludge handling characteristics of an engine lubricant composition, while minimizing the deterioration of engine seals.

A lubricating oil composition having greater than 50 wt % of a base oil and 0.1 wt % to 20 wt %, both based on the total weight of the lubricating oil composition, of a dispersant viscosity modifier obtainable by: A) reacting: a) at least one of a lactone of formula (I) or a derivative thereof: ##STR00001##
wherein X is oxygen, and R is an optionally substituted hydrocarbylene group having from 1 to 20 carbon atoms; and b) at least one compound selected from amines, alcohols and oxazolines; and B) reacting the reaction product of step A) onto an acylated olefin copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having a number average molecular weight of 5,000 to 200,000 g/mol as measured by GPC, with an acylating agent. Methods employing the lubricating oil compositions and uses of the lubricating compositions as engine oils are also described.

The present disclosure relates to viscosity index modifiers that have dispersant properties and lubricating oil compositions comprising said viscosity index modifiers. The viscosity index modifier is the reaction product of an acylated olefin copolymer, a polyamine, and a dicarboxylic acid or anhydride thereof that can react with a free primary amine of the polyamine to form a ring moiety. The disclosure also relates to the use of lubricant compositions comprising the viscosity index improvers of the disclosure for improving the soot or sludge handling characteristics of an engine lubricant composition, while minimizing the deterioration of engine seals.

Disclosed is a dispersant composition, suitable for use in lubricating oils. The dispersant composition is a reaction product of (i) a polyalkenyl succinimide post-treated with a post-treating agent selected from the group consisting of an organic carbonate, an epoxide, a lactone, a hydroxyaliphatic carboxylic acid, and combinations thereof; and (ii) an acylating agent.

A lubricating composition includes a sulfurized oxy-substituted aromatic polyol compound and an oil of lubricating viscosity. The sulfurized oxy-substituted aromatic polyol compound includes at least one of a sulfurized oxy-substituted aromatic polyol and a salt of a sulfurized oxy-substituted aromatic polyol. The compound is suitable as a replacement for detergents that contain C.sub.n alkyl phenols derived from oligomers of propylene.

Engine oil \s and methods for use in soot-producing engines. The engine oil contains a major amount of a base oil and a dispersant reaction product of A) a hydrocarbyl-dicarboxylic acid or anhydride, and B) at least one polyamine, that is post-treated with C) an aromatic carboxylic acid, an aromatic polycarboxylic acid, or an aromatic anhydride, wherein all carboxylic acid or anhydride groups of C) are attached directly to an aromatic ring. A molar ratio of carboxyl groups from components A) and C) to nitrogen atoms from component B) of from 0.9 to 1.3 is used to make the dispersant which also has a molar ratio of component C) to component B) of at least 0.4 and when component B) has an average of 4-6 nitrogen atoms per molecule, a molar ratio of A) to B) is from 1.0 to 1.6.