Lubricating composition comprising (i) base oil and (ii) a metal-free phosphonate compound having the general formula P(═O)(R.sup.1)(OR.sup.2)(OR.sup.3) wherein R.sup.1, R.sup.2 and R.sup.3 are the same or different and each independently selected from a straight chain or branched, saturated or unsaturated, C.sub.4-C.sub.22 alkyl group. The lubricating composition of the present invention provides improved engine durability, improved wear and friction reduction, improved fuel economy and excellent oxidative stability.

The invention provides a lubricant composition containing an oil of lubricating viscosity and a boron-containing en.) compound, wherein the boron containing compound comprises a borate ester comprising at least one alkyl group having a branch at the ? position or higher. The invention further relates to a method of lubricating an internal combustion engine with the lubricant composition.

The invention provides a lubricant composition containing an oil of lubricating viscosity and a boron-containing en.) compound, wherein the boron containing compound comprises a borate ester comprising at least one alkyl group having a branch at the ? position or higher. The invention further relates to a method of lubricating an internal combustion engine with the lubricant composition.

Lubricant compositions including an additive composition and methods for its use in engines that produce soot. The lubricant composition contains a base oil and an additive composition having (a) at least 0.05 percent by weight of a first dispersant that is a reaction product of A) a hydrocarbyl-dicarboxylic acid or anhydride, and B) at least one polyamine; and (b) at least 0.05 percent by weight, both based on a total weight of the lubricant composition, of a second dispersant that is a reaction product of A′) a hydrocarbyl-dicarboxylic acid or anhydride, and B′) at least one polyamine, wherein the reaction product is post-treated with C) an aromatic carboxylic acid, an aromatic polycarboxylic acid, or an aromatic anhydride wherein all carboxylic acid or anhydride groups are attached directly to an aromatic ring, and/or D) a non-aromatic dicarboxylic acid or anhydride having a number average molecular weight of less than about 500.

The present invention generally relates to lubricating oil compositions comprising a biobased base oil, methods of lubricating an engine with said lubricating oil compositions. Also disclosed is the use of said lubricating oil compositions in an engine.

The present invention generally relates to lubricating oil compositions comprising a biobased base oil, methods of lubricating an engine with said lubricating oil compositions. Also disclosed is the use of said lubricating oil compositions in an engine.

A hydraulic fluid includes an oil of lubricating viscosity and at least 2 wt. % of an ester of a carboxy group-containing interpolymer comprising units derived from a vinyl aromatic monomer and units derived from a carboxylic acid monomer. The interpolymer also contains nitrogen functionality. The hydraulic fluid is at least substantially free of polyacrylates and polymethacrylates.

Disclosed is a lubricating oil composition for low-friction sliding materials, which is used in a sliding mechanism where a DLC film containing hydrogen in an amount of from 5 atom % to 50 atom % is formed on at least one sliding surface. The lubricating oil composition contains, in the lubricant base oil therein and based on the total amount of the composition, (A) an organic zinc dithiophosphate in an amount of from 0.005% by mass to 0.12% by mass in terms of the phosphorus concentration therein, (B) an amine-based friction-reducing agent in an amount of from 0.05% by mass to 5.0% by mass, and (C) an alkaline earth metal salicylate-based detergent and/or an alkaline earth metal sulfonate-based detergent in an amount of from 0.05% by mass to 0.5% by mass in terms of the alkaline earth metal concentration therein, wherein the component (A) contains, based on the total amount of the composition, a zinc primary dialkyldithiophosphate in an amount of from 0.005% by mass to 0.05% by mass in terms of the phosphorus concentration therein.

A lubricating oil composition includes at least one base oil selected from the group consisting of a mineral oil-based lubricating oil, a synthetic oil-based lubricating oil, and a mixed oil thereof, zinc dialkyldithiophosphate X represented by Formula (1), and an acid phosphate ester amine salt Y represented by Formula (2), in which a content P.sub.X of the X is from 0.06% by mass to 0.08% by mass in terms of phosphorus concentration with respect to a total mass of the lubricating oil composition, and a content P.sub.Y of the Y is from 0.015% by mass to 0.025% by mass in terms of phosphorus concentration with respect to the total mass of the lubricating oil composition.

A lubricating oil composition includes at least one base oil selected from the group consisting of a mineral oil-based lubricating oil, a synthetic oil-based lubricating oil, and a mixed oil thereof, zinc dialkyldithiophosphate X represented by Formula (1), and an acid phosphate ester amine salt Y represented by Formula (2), in which a content P.sub.X of the X is from 0.06% by mass to 0.08% by mass in terms of phosphorus concentration with respect to a total mass of the lubricating oil composition, and a content P.sub.Y of the Y is from 0.015% by mass to 0.025% by mass in terms of phosphorus concentration with respect to the total mass of the lubricating oil composition.