The present invention addresses a problem of providing a grease composition containing a urea-based thickener and capable of appropriately maintaining the kinematic friction force in lubrication parts. The grease composition contains a base oil (A) and a urea-based thickener (B), wherein the base oil (A) has a kinematic viscosity at 40° C. of 100 mm.sup.2/s or more, and the particles containing the urea-based thickener (B) in the grease composition satisfy the following requirement (I). Requirement (I): the area-based arithmetic average particle diameter of the particles is 2.0 μm or less, as measured by a laser diffraction/scattering method.

A lubricating oil composition comprises an amide and at least one additive. A lubricating grease composition comprises a liquid amide, a thickener comprising a metal soap, and at least one additive. The amide in each composition is the reaction product of a secondary, branched amine and a carboxylic acid. The carboxylic acid may be a monocarboxylic acid or a dicarboxylic acid, including dimer acid. The amide is hydrolytically stable, and may be used to increase the hydrolytic stability of the lubricant oil or grease composition. Alternatively, the amide may be used to increase the additive solubility or detergency of the lubricant oil or grease composition.

The present invention relates to a lubricating oil composition and a continuously-variable transmission filled with the lubricating oil composition. The present invention also relates to a friction control method for a continuously-variable transmission, the method using the lubricating oil composition. This lubricating oil composition is characterized by containing: (A) a base oil; (B) a diamine; (C) a glycolic acid amide; and (D) a phosphorous ester. With this lubricating oil composition, it is possible to provide different wear characteristics between different parts, so in a preferable embodiment of the present invention, the lubricating oil composition is suitably used as a lubricating oil for variable transmissions, in particular, metal-belt continuously-variable transmissions.

The present invention relates to a lubricating oil composition and a continuously-variable transmission filled with the lubricating oil composition. The present invention also relates to a friction control method for a continuously-variable transmission, the method using the lubricating oil composition. This lubricating oil composition is characterized by containing: (A) a base oil; (B) a diamine; (C) a glycolic acid amide; and (D) a phosphorous ester. With this lubricating oil composition, it is possible to provide different wear characteristics between different parts, so in a preferable embodiment of the present invention, the lubricating oil composition is suitably used as a lubricating oil for variable transmissions, in particular, metal-belt continuously-variable transmissions.

A lubricating oil composition comprises an amide and at least one additive. A lubricating grease composition comprises a liquid amide, a thickener comprising a metal soap, and at least one additive. The amide in each composition is the reaction product of a secondary, branched amine and a carboxylic acid. The carboxylic acid may be a monocarboxylic acid or a dicarboxylic acid, including dimer acid. The amide is hydrolytically stable, and may be used to increase the hydrolytic stability of the lubricant oil or grease composition. Alternatively, the amide may be used to increase the additive solubility or detergency of the lubricant oil or grease composition.

The grease composition including: a base oil having a kinematic viscosity of 5 to 30 mm.sup.2/s at 100° C., a thickener, a polymer having a weight average molecular weight of 1,000 to 500,000, and an aliphatic amide compound. The grease composition is used for sliding between a metal member and a resin member, and capable of reducing friction between them.

The grease composition including: a base oil having a kinematic viscosity of 5 to 30 mm.sup.2/s at 100° C., a thickener, a polymer having a weight average molecular weight of 1,000 to 500,000, and an aliphatic amide compound. The grease composition is used for sliding between a metal member and a resin member, and capable of reducing friction between them.

The present disclosure relates to methods for improving phosphorus retention and improving antiwear performance in an internal combustion engine of a hybrid vehicle, comprising lubricating the internal combustion engine of the hybrid vehicle with a lubricating oil composition comprising: greater than 50 wt. % of a base oil of lubricating viscosity; and an amount of one or more zinc dialkyl dithiophosphate compound(s) sufficient to provide: from about 100 ppmw phosphorus to about 1000 ppmw phosphorus, based on a total weight of the lubricating oil composition; and from about 10 ppmw zinc to about 1200 ppmw zinc, based on the total weight of the lubricating oil composition.

The present disclosure relates to methods for improving phosphorus retention and improving antiwear performance in an internal combustion engine of a hybrid vehicle, comprising lubricating the internal combustion engine of the hybrid vehicle with a lubricating oil composition comprising: greater than 50 wt. % of a base oil of lubricating viscosity; and an amount of one or more zinc dialkyl dithiophosphate compound(s) sufficient to provide: from about 100 ppmw phosphorus to about 1000 ppmw phosphorus, based on a total weight of the lubricating oil composition; and from about 10 ppmw zinc to about 1200 ppmw zinc, based on the total weight of the lubricating oil composition.

A lubricant composition having greater than 50 percent by weight of a base oil, a dispersant composition comprising: i) a first dispersant comprising one or more reaction products of at least one polyisobutenyl succinic acid or anhydride having a polyisobutenyl group with a number average molecular weight that is less than or equal to 1300, and at least one polyamine; and ii) a second dispersant comprising one or more reaction products of at least one polyisobutenyl succinic acid or anhydride having a polyisobutenyl group with a number average molecular weight greater than 1300, and at least one polyamine; and at least one ashless antioxidant; and wherein a weight ratio of the second dispersant to the dispersant composition is 0.66:1 to 1:1 or a ratio of the weight percentages of nitrogen contributed by the second dispersant to nitrogen of the dispersant composition is 0.62:1 to 1:1.