The present invention provides a lubricating oil composition comprising: (A) a lubricant base oil including at least one type selected from mineral oil, PAO, and GTL (gas-to-liquid) base oils; (B) a compound having a structure obtained by independently subjecting propylene oxide to addition polymerization with an alcohol or a structure obtained by subjecting a combination of propylene oxide with ethylene oxide and/or butylene oxide to addition polymerization with an alcohol, and being configured so that polyalkylene glycol (PAG) with an oxygen/carbon weight ratio of 0.35 or more and less than 0.45 and/or one or both terminal hydroxyl groups in the polyalkylene glycol (PAG) are blocked; and (C) a fatty acid ester having an oxygen/carbon weight ratio of 0.05 to 0.35.

The present invention provides a lubricating oil composition comprising: (A) a lubricant base oil including at least one type selected from mineral oil, PAO, and GTL (gas-to-liquid) base oils; (B) a compound having a structure obtained by independently subjecting propylene oxide to addition polymerization with an alcohol or a structure obtained by subjecting a combination of propylene oxide with ethylene oxide and/or butylene oxide to addition polymerization with an alcohol, and being configured so that polyalkylene glycol (PAG) with an oxygen/carbon weight ratio of 0.35 or more and less than 0.45 and/or one or both terminal hydroxyl groups in the polyalkylene glycol (PAG) are blocked; and (C) a fatty acid ester having an oxygen/carbon weight ratio of 0.05 to 0.35.

Provided are lubricant compositions comprising a hydrocarbon base oil and a polyoxybutylene polymer prepared by polymerizing butylene oxide with a monol initiator and having a number average molecular weight ranging from 800 g/mol to 1200 g/mol. The polyoxybutylene polymer functions as a highly active friction-modifier additive.

Provided are lubricant compositions comprising a hydrocarbon base oil and a polyoxybutylene polymer prepared by polymerizing butylene oxide with a monol initiator and having a number average molecular weight ranging from 800 g/mol to 1200 g/mol. The polyoxybutylene polymer functions as a highly active friction-modifier additive.

A lubricating oil composition according to one embodiment of the present invention contains an oxygen-containing synthetic base oil having an oxygen content (A) of from 15 to 40 mass % and a kinetic viscosity at 100 C. of from 0.5 to 50 mm.sup.2/s, and a viscosity index improver that is an oxygen-containing compound having an oxygen content (B) of from 15 to 40 mass % and a kinetic viscosity at 100 C. of 11,000 mm.sup.2/s or more, a mass ratio of the oxygen-containing synthetic base oil and the viscosity index improver being from 99.5:0.5 to 75:25, and a ratio (A/B) of the oxygen content (A) of the oxygen-containing synthetic base oil to the oxygen content (B) of the viscosity index improver being in a range of from 0.5 to 2.

A lubricating oil composition according to one embodiment of the present invention contains an oxygen-containing synthetic base oil having an oxygen content (A) of from 15 to 40 mass % and a kinetic viscosity at 100 C. of from 0.5 to 50 mm.sup.2/s, and a viscosity index improver that is an oxygen-containing compound having an oxygen content (B) of from 15 to 40 mass % and a kinetic viscosity at 100 C. of 11,000 mm.sup.2/s or more, a mass ratio of the oxygen-containing synthetic base oil and the viscosity index improver being from 99.5:0.5 to 75:25, and a ratio (A/B) of the oxygen content (A) of the oxygen-containing synthetic base oil to the oxygen content (B) of the viscosity index improver being in a range of from 0.5 to 2.

A capped oil soluble polyalkylene glycol has the following structure: R.sup.1O(AO).sub.nR.sup.2 where: R.sup.1 is a linear or branched alkyl or aryl with one to 18 carbon atoms; AO refers to residuals of monomers selected from 1,2-butylene oxide and 1,2-propylene oxide selected so that at least 50 weight-percent of the (AO).sub.n component is 1,2-butylene oxide residuals; n is selected to provide a kinematic viscosity at 100 degrees Celsius of less than 5 centiStokes for the non-capped polyalkylene glycol; and R.sup.2 is a linear or branched alkyl or aryl having from 1-8 carbon atoms and wherein the capped oil soluble polyalkylene glycol is characterized by having a kinematic viscosity of less than 4.5 centiStokes at 100 degrees Celsius and a viscosity index of greater than 150.

A capped oil soluble polyalkylene glycol has the following structure: R.sup.1O(AO).sub.nR.sup.2 where: R.sup.1 is a linear or branched alkyl or aryl with one to 18 carbon atoms; AO refers to residuals of monomers selected from 1,2-butylene oxide and 1,2-propylene oxide selected so that at least 50 weight-percent of the (AO).sub.n component is 1,2-butylene oxide residuals; n is selected to provide a kinematic viscosity at 100 degrees Celsius of less than 5 centiStokes for the non-capped polyalkylene glycol; and R.sup.2 is a linear or branched alkyl or aryl having from 1-8 carbon atoms and wherein the capped oil soluble polyalkylene glycol is characterized by having a kinematic viscosity of less than 4.5 centiStokes at 100 degrees Celsius and a viscosity index of greater than 150.

Provided are polyalkoxylates that are prepared by alkoxylating polytetrahydrofurane with butylene oxide for use in lubricant compositions and/or for reducing friction in a driveline.

Provided are polyalkoxylates that are prepared by alkoxylating polytetrahydrofurane with butylene oxide for use in lubricant compositions and/or for reducing friction in a driveline.