Provided are a lubricating oil composition used in a diesel engine equipped with a forced-induction compressor, containing a base oil (A) containing a poly-α-olefin (A1), and a viscosity index improver (B) having an SSI (shear stability index) of 20 or less, having a distillation amount of a light fraction of 496° C. or less in a gas chromatography distillation test of less than 80% by volume, having a high retention of the effect of suppressing the formation of deposits that may occur inside the compressor, and being capable of retaining a high efficiency of the compressor for a long period of time, in the use thereof in a diesel engine equipped with a forced-induction compressor having an outlet temperature of the compressor becoming a high temperature reaching 190° C. or more, and a method for using the lubricating oil composition.

A lubricating composition comprises at least 50 percent by mass, based on the mass of the composition of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble poly(2-oxazine) polymer. The polymer has the repeat unit: ##STR00001##
where the number (n) of repeat units is an integer between 4 and 500, such as between 4 and 400. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. R.sup.1 comprises a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

Hydrogenated polymers with a radial structure having a core made up of calixarenes of the general formula (I), to the core of which is linked a number P of hydrogenated linear polymer segments selected from: —hydrogenated homopolymers or co-polymers of conjugated dienes; or—hydrogenated co-polymers of said conjugated dienes and monoalkenyl arenes, and—mixtures thereof said formula (I) in which: —R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from hydrogen; a group containing carbon and hydrogen; a group also containing heteroatoms in addition to carbon and hydrogen; a group also containing silicon in addition to carbon, hydrogen and heteroatoms; —one of the two substituents R.sub.5 and R.sub.6 is hydrogen, while the other may be hydrogen or alkyl, with a number of carbon atoms between 1 and 6, preferably methyl and ethyl; —n is an integer in the range between 4 and 16. ##STR00001##

The present disclosure provides a lubricating composition that includes one or more boron-containing compounds and method of forming the same. The lubricating composition includes one or more boron-containing compounds, one or more metal-based detergents, one or more amine-based antioxidants, one or more phenol-based antioxidants, and a base oil balance. The lubricating composition includes greater than or equal to about 60 ppm to less than or equal to about 300 ppm of boron atoms that define the one or more boron-containing compounds; greater than or equal to about 1,100 ppm of metal atoms that define the one or more metal-based detergents; greater than or equal to about 0.70 wt. % to less than or equal to about 2.00 wt. % of the one or more amine-based antioxidants; and greater than or equal to about 0.30 wt. % to less than or equal to about 2.00 wt. %, of the one or more phenol-based antioxidants.

The present disclosure provides a lubricating composition that includes one or more boron-containing compounds and method of forming the same. The lubricating composition includes one or more boron-containing compounds, one or more metal-based detergents, one or more amine-based antioxidants, one or more phenol-based antioxidants, and a base oil balance. The lubricating composition includes greater than or equal to about 60 ppm to less than or equal to about 300 ppm of boron atoms that define the one or more boron-containing compounds; greater than or equal to about 1,100 ppm of metal atoms that define the one or more metal-based detergents; greater than or equal to about 0.70 wt. % to less than or equal to about 2.00 wt. % of the one or more amine-based antioxidants; and greater than or equal to about 0.30 wt. % to less than or equal to about 2.00 wt. %, of the one or more phenol-based antioxidants.

The present invention relates to the field of multipurpose lubricants which may be used in the various components of automotive vehicles, notably in the engine, the transmission or the hydraulic circuit.

The invention relates to the use of at least one polymer which improves the viscosity index, chosen from hydrogenated copolymers of diene and of aromatic vinyl, in a lubricant composition for decreasing the viscosity of said lubricant composition in the course of the use of said lubricant composition during the lubrication of the various components of an industrial vehicle, notably of a diesel engine industrial vehicle, such as the engine, the gearbox and the hydraulic circuit, said lubricant composition undergoing at least one thermal shear during its use.

The invention provides a lubricating composition comprising a low viscosity base oil and a synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate polymer, and a metal-free anti-wear agent. The invention also provides a method of lubricating an internal combustion engine using such a lubricating composition.

Provided are a lubricating oil composition used in a diesel engine equipped with a forced-induction compressor, containing a base oil (A) containing a poly--olefin (A1), and a viscosity index improver (B) having an SSI (shear stability index) of 20 or less, having a distillation amount of a light fraction of 496 C. or less in a gas chromatography distillation test of less than 80% by volume, having a high retention of the effect of suppressing the formation of deposits that may occur inside the compressor, and being capable of retaining a high efficiency of the compressor for a long period of time, in the use thereof in a diesel engine equipped with a forced-induction compressor having an outlet temperature of the compressor becoming a high temperature reaching 190 C. or more, and a method for using the lubricating oil composition.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble copolymer. The copolymer comprises units (a) and units (b):
N(COR.sup.1)CH.sub.2CH.sub.2(a)
N(COR.sup.2)CH.sub.2CH.sub.2CH.sub.2(b)
wherein the polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit (a) or (b), the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. R.sup.1 and R.sup.2 are the same or different and comprise a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by weight, based on the weight of the composition, of a poly(2-oxazoline) polymer. The polymer has the repeat unit:
N(COR.sup.1)CH.sub.2CH.sub.2
wherein the number of repeat units (n) in the polymer is an integer between 4 and 1000, such as between 4 and 500. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. At least 5% of the total number of the groups R.sup.1 in the polymer comprise alkenyl groups having between 15 and 20 carbon atoms.