Disclosed is an oil soluble polyester composition, suitable for use as a dispersant in lubricating oils. The oil soluble polyester composition is prepared by reacting (a) a hydrocarbyl-substituted succinic acylating agent and (b) a di-hydroxyalkyl-substituted tertiary amine compound selected from a N,N-di-hydroxyalkyl-substituted tertiary monoamine and a N,N-di-hydroxyalkyl-substituted tertiary diamine.

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.

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.

An object of the present invention is to provide a lubricant composition having excellent lubrication properties in rigorous conditions such as a high temperature and/or a high pressure. The present invention relates to lubricant composition containing a condensate A which is obtained by condensing at least: an alkylene oxide adduct a1 of trihydric or more polyhydric alcohol formed by adding alkylene oxide to at least one hydroxyl group of the trihydric or more polyhydric alcohol; a divalent or more polyvalent carboxylic acid a2 or a precursor of the divalent or more polyvalent carboxylic acid a2; and at least one of a monovalent carboxylic acid a3, a precursor of the monovalent carboxylic acid a3, or monohydric alcohol a4.

An object of the present invention is to provide a lubricant composition having excellent lubrication properties in rigorous conditions such as a high temperature and/or a high pressure. The present invention relates to lubricant composition containing a condensate A which is obtained by condensing at least: an alkylene oxide adduct a1 of trihydric or more polyhydric alcohol formed by adding alkylene oxide to at least one hydroxyl group of the trihydric or more polyhydric alcohol; a divalent or more polyvalent carboxylic acid a2 or a precursor of the divalent or more polyvalent carboxylic acid a2; and at least one of a monovalent carboxylic acid a3, a precursor of the monovalent carboxylic acid a3, or monohydric alcohol a4.

A polyester composition, suitable for use as a dispersant in lubricating oils, is disclosed. The polyester composition is prepared by reacting (a) an acylating agent selected from an aliphatic-substituted succinic acylating agent, an aromatic polycarboxylic acylating agent, and combinations thereof; and (b) a hydroxyalkyl-substituted tertiary amine compound of the following structure: ##STR00001##
wherein R is a C.sub.1-24 aliphatic group; R in each of the x (RO), y (RO) and z (RO) groups is independently C.sub.2-4 alkylene; x+y is in a range of 2 to 7; and z is in a range of 1 to 5.

A polyester composition, suitable for use as a dispersant in lubricating oils, is disclosed. The polyester composition is prepared by reacting (a) an acylating agent selected from an aliphatic-substituted succinic acylating agent, an aromatic polycarboxylic acylating agent, and combinations thereof; and (b) a hydroxyalkyl-substituted tertiary amine compound of the following structure: ##STR00001##
wherein R is a C.sub.1-24 aliphatic group; R in each of the x (RO), y (RO) and z (RO) groups is independently C.sub.2-4 alkylene; x+y is in a range of 2 to 7; and z is in a range of 1 to 5.

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.

A polyester composition, suitable for use as a dispersant in lubricating oils, is disclosed. The polyester composition is prepared by reacting (a) an acylating agent selected from an aliphatic-substituted succinic acylating agent, an aromatic polycarboxylic acylating agent, and combinations thereof; and (b) a hydroxyalkyl-substituted tertiary amine compound of the following structure:

##STR00001##

wherein R is a C.sub.1-24 aliphatic group; R in each of the x (RO), y (RO) and z (RO) groups is independently C.sub.2-4 alkylene; x+y is in a range of 2 to 7; and z is in a range of 1 to 5.

A polyester composition, suitable for use as a dispersant in lubricating oils, is disclosed. The polyester composition is prepared by reacting (a) an acylating agent selected from an aliphatic-substituted succinic acylating agent, an aromatic polycarboxylic acylating agent, and combinations thereof; and (b) a hydroxyalkyl-substituted tertiary amine compound of the following structure:

##STR00001##

wherein R is a C.sub.1-24 aliphatic group; R in each of the x (RO), y (RO) and z (RO) groups is independently C.sub.2-4 alkylene; x+y is in a range of 2 to 7; and z is in a range of 1 to 5.