Lubricating compositions containing a phosphorus-containing salt of an acylated ethylene-α-olefin polymer substituted with an aliphatic polyamine having at least one primary or secondary amine, the lubricating composition having a total phosphorus content in an amount of 200 ppm to 600 ppm by weight of the lubricating composition. The phosphorus-containing salt additive described herein can be used as an anti-wear agent in lubricating composition for diesel engines.

A lubricating oil composition contains a base oil and a rust inhibitor, in which the base oil has a gas chromatogram measured by gas chromatography satisfying the particular condition (), and the rust inhibitor is at least one selected from a first rust inhibitor, a second rust inhibitor, a third rust inhibitor, and a fourth rust inhibitor, and satisfies the particular condition ().

A lubricating composition includes at least one base oil, at least one borated dispersant, at least two antioxidants selected from amine antioxidants, phenolic antioxidants substituted with one or more linear or branched alkyl groups having from 1 to 30 carbon atoms, and mixtures thereof, and at least one phosphite polymer having the formula (I) wherein: each of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be independently selected from the C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers and YOH groups; Y is selected from C2-C40 alkylene, C2-C40 alkyl lactone, R.sup.7N(R.sup.8)R.sup.9 groups, in which R.sup.7, R.sup.8 and R.sup.9 are independently selected from hydrogen, C1-C20 alkyl, C3-C22 alkenyi, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers; m is an integer from 2 to 100; n is an integer from 1 to 1000.

A lubricating composition includes at least one base oil, at least one borated dispersant, at least two antioxidants selected from amine antioxidants, phenolic antioxidants substituted with one or more linear or branched alkyl groups having from 1 to 30 carbon atoms, and mixtures thereof, and at least one phosphite polymer having the formula (I) wherein: each of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be independently selected from the C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers and YOH groups; Y is selected from C2-C40 alkylene, C2-C40 alkyl lactone, R.sup.7N(R.sup.8)R.sup.9 groups, in which R.sup.7, R.sup.8 and R.sup.9 are independently selected from hydrogen, C1-C20 alkyl, C3-C22 alkenyi, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers; m is an integer from 2 to 100; n is an integer from 1 to 1000.

The disclosed technology relates to a lubricant composition for automotive or industrial gears, as well as axles and bearings, the automotive or industrial gear oil containing an oil of lubricating viscosity, an optional phosphate and/or thiophosphate compound, a particular sulfurized olefin, either a metal thiophosphate compound, such as zinc dialkyldithiophosphate, a thiadiazole functionalized dispersant, or a mixture thereof, and a hydroxyl/amine containing booster, as well as a method of improving automotive or industrial gear operating efficiency and temperature by lubricating such automotive or industrial gears with the automotive or industrial gear oil.

There has been a need for a novel lubricating oil composition which has characteristics (for example, scuffing resistance and copper corrosion resistance) that are suitable for lubrication of various mechanisms that are incorporated in a device. The present invention provides a lubricating oil composition which contains (A) a base oil and (B) a phosphite ester that has at least one sulfur atom-containing group having 2 to 20 carbon atoms, the group having at least one (S) x- group (wherein x is an integer of 1 or more) between two adjacent carbon atoms in the structure of an alkyl group, wherein: the content of a thiadiazole compound is less than 0.05% by mass based on the total amount of the lubricating oil composition; and the kinematic viscosity of the lubricating oil composition at 100 C. is 4.2 mm.sup.2/s or more.

There has been a need for a novel lubricating oil composition which has characteristics (for example, scuffing resistance and copper corrosion resistance) that are suitable for lubrication of various mechanisms that are incorporated in a device. The present invention provides a lubricating oil composition which contains (A) a base oil and (B) a phosphite ester that has at least one sulfur atom-containing group having 2 to 20 carbon atoms, the group having at least one (S) x- group (wherein x is an integer of 1 or more) between two adjacent carbon atoms in the structure of an alkyl group, wherein: the content of a thiadiazole compound is less than 0.05% by mass based on the total amount of the lubricating oil composition; and the kinematic viscosity of the lubricating oil composition at 100 C. is 4.2 mm.sup.2/s or more.