The disclosed technology relates to the use of toxicologically acceptable hydrocarbyl- (e.g. alkyl-) phenol detergents and their salts in automotive lubricating oils, such as, for example, automatic or manual transmissions.

There is provided a press-fit lubricant composition comprising an unsaturated compound with an iodine value of 100 or more.

The present invention provides a lubricating oil composition comprising: a lubricating base oil; 1.0% by mass or more and 15.0% by mass or less of a dispersant poly(meth)acrylate compound having the weight average molecular weight of 20000 or more and 200000 or less; 0.05% by mass or more and 6.0% by mass or less of a thiadiazole compound; 1.5% by mass or more and 4.0% by mass or less of a polysulfide compound; and 0.2% by mass or more and 1.5% by mass or less of a friction modifier, based on the total amount of the lubricating oil composition, wherein the mass ratio of the polysulfide compound content to the thiadiazole compound content (polysulfide compound/thiadiazole compound) is 0.4 or more and 50 or less, and the kinematic viscosity at 100 C. of the lubricating oil composition is 7.0 mm.sup.2/s or more and 35.0 mm.sup.2/s or less.

An additive for lubricating oil may include a phosphite ester compound (A) having a specific structure and a phosphite ester compound (B) having a specific structure, wherein the (A):(B) mass ratio of the phosphite ester compound (A) to the phosphite ester compound (B) is in a range of from 99:1 to 80:20. Such an additive may be provided to a lubricating oil, capable of imparting wear resistance and demulsibility with respect to a base oil for lubricating oil, and to impart durability even in the presence of water.

The present invention relates to an antiwear agent and lubricating compositions thereof. The invention further provides for a method of lubricating a driveline device application by employing a lubricating composition containing the antiwear agent.

An axle oil composition having enhanced fuel efficiency and low viscosity is provided, wherein the axle oil composition contains 40 to 70 wt % of poly alpha olefin (PAO) synthetic oil; 5 to 35 wt % of an oil soluble poly alkylene glycol (OSP) synthetic oil; 15 to 20 wt % of an ester-based viscosity modifier; 0.05 to 0.5 wt % of calcite; and 5 to 20 wt % of additive, wherein the axle oil composition having enhanced fuel efficiency and low viscosity has average kinematic viscosity at 100 C. of 11.5 to 13.5 cSt and average kinematic viscosity at 40 C. of 65 to 75 cSt and forms an oil film having a thickness of 85 to 96 nm even at low viscosity, largely improving durability and fuel efficiency of a vehicle.

The present invention relates to an antiwear agent and lubricating compositions thereof. The invention further provides for a method of lubricating a driveline device application by employing a lubricating composition containing the antiwear agent.

Disclosed is a lubricating oil composition for gear oil, comprising a lubricating base oil having a kinematic viscosity at 40 C. of 140 to 350 mm.sup.2/s, a copolymer of an -olefin and an ester monomer having a polymerizable unsaturated bond, a performance additive containing phosphorus and sulfur, and a poly(meth)acrylate pour-point depressant.

The present patent application relates to a method for reducing wear and tear on mechanical parts that are in contact with each other in an internal combustion engine by using a lubricating composition comprising: at least one base oil; at least one oxothiomolybdate salt; and at least one anti-wear compound;
wherein at least one of the said parts includes a surface that comprises an amorphous carbon type coating.

A lubricating oil composition is provided by blending a base oil and an additive, the additive including (a) at least one of an alkaline earth metal sulfonate, an alkaline earth metal salicylate and an alkaline earth metal phenate, (b) a sulfur-containing phosphorus compound, and (c) a thiadiazole compound. A product ((c)P) of a mass (mass %) of the component (c) and a mass (mass ppm) of a phosphorus element in the component (b) in the composition is in a range from 1 to 50.