Provided is a lubricating oil composition for use in internal-combustion engines, containing a base oil (A), an ashless dispersant (B) containing a non-boronated alkenylsuccinic acid imide (B1) and a boronated alkenylsuccinic acid imide (B2), a thiadiazole compound (C), and an aromatic carboxylate (D) having one or more hydroxy groups, wherein the content of the component (C) is 0.2 to 1.2% by mass based on the total amount of the lubricating oil composition, the content of a zinc dithiophosphate is, as calculated in terms of zinc atoms, less than 500 ppm by mass based on the total amount of the lubricating oil composition, and the content of a metal-based detergent is, as calculated in terms of metal atoms, less than 600 ppm by mass based on the total amount of the lubricating oil composition.

Certain citric esters and amides, and certain mixtures thereof, e.g., mixtures comprising citrate oligomers, exhibit excellent anti-wear activity in lubricants. Many of these compounds or mixtures of compounds also exhibit a high degree of anti-wear synergy in combination with zinc dihydrocarbyldithiophosphates. The compounds of the invention are thus valuable tools that can allow one to reduce the amounts of zinc, and phosphates, that are used in the lubricant without sacrificing anti-wear performance.

Certain citric esters and amides, and certain mixtures thereof, e.g., mixtures comprising citrate oligomers, exhibit excellent anti-wear activity in lubricants. Many of these compounds or mixtures of compounds also exhibit a high degree of anti-wear synergy in combination with zinc dihydrocarbyldithiophosphates. The compounds of the invention are thus valuable tools that can allow one to reduce the amounts of zinc, and phosphates, that are used in the lubricant without sacrificing anti-wear performance.

Provided are a lubricating oil composition containing a component (A): a succinimide having an alkenyl group or an alkyl group, a component (B): a primary amine having a hydrocarbon group having 12 or more and 24 or less carbon atoms, a component (C): a fatty acid amide compound, and a component (D): an amide compound having a specific structure, and capable of satisfying both a high clutch capacity and a long anti-shudder lifetime; and a lubrication method and a transmission using the composition.

Provided are a lubricating oil composition containing a component (A): a succinimide having an alkenyl group or an alkyl group, a component (B): a primary amine having a hydrocarbon group having 12 or more and 24 or less carbon atoms, a component (C): a fatty acid amide compound, and a component (D): an amide compound having a specific structure, and capable of satisfying both a high clutch capacity and a long anti-shudder lifetime; and a lubrication method and a transmission using the composition.

Novel friction reducing additives provide friction modification at a lower effective concentration when added to a motor oil base. A friction reducing motor oil composition may include motor oil base and a friction reducing additive having the structure of the general formula (I): ##STR00001##
wherein: R.sub.1 is a straight or branched C.sub.5-C.sub.30 alkyl or alkenyl; R.sub.2 is H, or a straight or branched alkyl of C.sub.1-C.sub.10; R.sub.3 is H, or a straight or branched alkyl of C.sub.1-C.sub.10; P is 0 or C.sub.1; n is C.sub.1-C.sub.5; and m is C.sub.0-C.sub.5.

Novel friction reducing additives provide friction modification at a lower effective concentration when added to a motor oil base. A friction reducing motor oil composition may include motor oil base and a friction reducing additive having the structure of the general formula (I): ##STR00001##
wherein: R.sub.1 is a straight or branched C.sub.5-C.sub.30 alkyl or alkenyl; R.sub.2 is H, or a straight or branched alkyl of C.sub.1-C.sub.10; R.sub.3 is H, or a straight or branched alkyl of C.sub.1-C.sub.10; P is 0 or C.sub.1; n is C.sub.1-C.sub.5; and m is C.sub.0-C.sub.5.

The present invention provides a preservative composition to prevent and/or reduce corrosion on a metal surface comprising an anhydride-derived amide and an oil and/or a solvent, wherein the anhydride-derived amide is present in an amount in the range of from 0.01-50 wt %, based on the total weight of the preservative composition. The invention also provides a preservative composition comprising in addition a sulfonate composition; a metal article having a coating thereon which coating comprises the present preservative composition; and the use of the present preservative composition to prevent and/or reduce corrosion on a metal surface.

The present invention provides a preservative composition to prevent and/or reduce corrosion on a metal surface comprising an anhydride-derived amide and an oil and/or a solvent, wherein the anhydride-derived amide is present in an amount in the range of from 0.01-50 wt %, based on the total weight of the preservative composition. The invention also provides a preservative composition comprising in addition a sulfonate composition; a metal article having a coating thereon which coating comprises the present preservative composition; and the use of the present preservative composition to prevent and/or reduce corrosion on a metal surface.

The instant disclosure is directed to a method of lubricating a sump-lubricated, high efficiency, gasoline-fueled internal combustion engine. Said method involves supplying to the engine a lubricating composition comprising an oil of lubricating viscosity, an anti-wear agent, an ashless antioxidant, a metal-containing detergent, an ashless polyolefin dispersant, and (f) a polymeric viscosity modifier. The disclosure further provides a method of operating a high efficiency sump-lubricated gasoline-fueled internal combustion engine while maintaining or improving at least one of durability, deposit control, oxidation control, fuel economy, and resistance to knock and stochastic pre-ignition.