The refrigerating machine oil according to the present invention comprises a polyalkylene glycol represented by the following formula (1):
R.sup.1(OR.sup.3).sub.nOR.sup.2(1)
[R.sup.1 and R.sup.2 may be the same or different from each other and each represent a hydrogen atom, an alkyl group having from 1 to 5 carbon atoms, or an acyl group having from 2 to 5 carbon atoms, R.sup.3 represents an alkylene group having from 2 to 4 carbon atoms, n represents an integer such that a number average molecular weight of the polyalkylene glycol represented by the formula (1) is from 1000 to 2500] the polyalkylene glycol having a ratio of the weight average molecular weight Mw to the number average molecular weight Mn, Mw/Mn, of from 1.00 to 1.15, the refrigerating machine oil being used with a mildly flammable hydrofluorocarbon refrigerant.

In the field of lubricating compositions for motor vehicles, there is disclosed a lubricating composition of a grade according to the SAEJ300 classification defined by the formula (X) W (Y) wherein X represents 0 or 5 and Y represents an integer ranging from 4 to 20. This lubricating composition includes at least one polyalphaolefinic oil (PAO), from 10 to 80% by weight of the composition of at least one oil of group V and at least one comb polymer. Also isclosed is the use of this lubricating composition for improving the Fuel Eco (FE) of a lubricant or for reducing the fuel consumption of an engine, in particular a motor vehicle engine, notably a motor of a hybrid vehicle.

In the field of lubricating compositions for motor vehicles, there is disclosed a lubricating composition of a grade according to the SAEJ300 classification defined by the formula (X) W (Y) wherein X represents 0 or 5 and Y represents an integer ranging from 4 to 20. This lubricating composition includes at least one polyalphaolefinic oil (PAO), from 10 to 80% by weight of the composition of at least one oil of group V and at least one comb polymer. Also isclosed is the use of this lubricating composition for improving the Fuel Eco (FE) of a lubricant or for reducing the fuel consumption of an engine, in particular a motor vehicle engine, notably a motor of a hybrid vehicle.

Lubricating oil compositions comprise one or more polytetrahydrofuranes that are prepared by alkoxylating polytetrahydrofurane with at least one C8-C30 epoxy alkane.

The presently claimed invention is directed to the use of polyethylene glycols that are prepared by alkoxylating polyethylene glycol with at least one C.sub.8-C.sub.30 epoxy alkane in lubricating oil compositions.

The presently claimed invention is directed to the use of polyethylene glycols that are prepared by alkoxylating polyethylene glycol with at least one C.sub.8-C.sub.30 epoxy alkane in lubricating oil compositions.

A lubricant formulation contains: (a) at least 50 weight-percent hydrocarbon base oil; (b) five to 50 weight-percent of an oil soluble polyalkylene glycol selected from monol, diol and triol initiated 1,2-butylene oxide homopolymer and monol initiated copolymers of 1,2-butylene oxide and propylene oxide; and (c) 0.1 to five weight-percent or less of a sulfurized olefin; where weight-percent is based on total lubricant formulation weight.

A lubricant formulation contains: (a) at least 50 weight-percent hydrocarbon base oil; (b) five to 50 weight-percent of an oil soluble polyalkylene glycol selected from monol, diol and triol initiated 1,2-butylene oxide homopolymer and monol initiated copolymers of 1,2-butylene oxide and propylene oxide; and (c) 0.1 to five weight-percent or less of a sulfurized olefin; where weight-percent is based on total lubricant formulation weight.

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.