Provided is a method for improving oxidation resistance and deposit resistance of a lubricating oil for use in lubricating a mechanical component. The method includes the step of providing the lubricating oil to the mechanical component and measuring the improved oxidation and deposit resistance. The lubricating oil includes a lubricating oil base stock at from 0 to 80 wt %, at least one branched isoparaffin having a mole % of epsilon carbon as measured by C.sub.13 NMR of less than or equal to 10% at from 20 to 80 wt %, at least one viscosity modifier at from 5 to 20 wt %, and one or more other lubricating oil additives. The oxidation resistance in the CEC L-109 oxidation resistance test is improved to greater than 310 hours to achieve a 100% viscosity increase and the deposit resistance in the TEOST 33C is improve to total deposits of less than 45 mg as compared to oxidation resistance and deposit resistance achieved using a lubricating oil not containing the at least one branched isoparaffin.

Provided is a method for improving oxidation resistance and deposit resistance of a lubricating oil for use in lubricating a mechanical component. The method includes the step of providing the lubricating oil to the mechanical component and measuring the improved oxidation and deposit resistance. The lubricating oil includes a lubricating oil base stock at from 0 to 80 wt %, at least one branched isoparaffin having a mole % of epsilon carbon as measured by C.sub.13 NMR of less than or equal to 10% at from 20 to 80 wt %, at least one viscosity modifier at from 5 to 20 wt %, and one or more other lubricating oil additives. The oxidation resistance in the CEC L-109 oxidation resistance test is improved to greater than 310 hours to achieve a 100% viscosity increase and the deposit resistance in the TEOST 33C is improve to total deposits of less than 45 mg as compared to oxidation resistance and deposit resistance achieved using a lubricating oil not containing the at least one branched isoparaffin.

A lubricant composition comprising a) a synthetic poly-alpha-olefin base fluid; b) an organomolybdenum friction modifier; c) an alkylphosphorothiolate and a hydrocarbylamine anti-wear combination; and d) a dihydrocarbyl dithiophosphate extreme pressure additive and optionally one or more of e) a copper corrosion inhibitor; f) an anti-foam agent; g) a solubilizing agent; h) polymeric viscosity index improver; and i) an oligomeric viscosity modifier is highly suitable for use in the synchronizer of a transmission.

A lubricant composition comprising a) a synthetic poly-alpha-olefin base fluid; b) an organomolybdenum friction modifier; c) an alkylphosphorothiolate and a hydrocarbylamine anti-wear combination; and d) a dihydrocarbyl dithiophosphate extreme pressure additive and optionally one or more of e) a copper corrosion inhibitor; f) an anti-foam agent; g) a solubilizing agent; h) polymeric viscosity index improver; and i) an oligomeric viscosity modifier is highly suitable for use in the synchronizer of a transmission.

A lubricating oil composition, a method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine, and a use of a lubricant composition to reduce LSPI events in such an engine. Preferably, the composition comprises a detergent package comprising a borated calcium detergent, wherein the detergent package provides a calcium content in the composition of at least 0.12 mass %, based on the total mass of the composition, and wherein the borated calcium detergent provides a boron content in the composition of at least 100 ppmm, based on the total mass of the composition. Optionally, the composition comprises a first detergent comprising a calcium detergent, and a second detergent comprising a borated calcium detergent.

A lubricating oil composition, a method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine, and a use of a lubricant composition to reduce LSPI events in such an engine. Preferably, the composition comprises a detergent package comprising a borated calcium detergent, wherein the detergent package provides a calcium content in the composition of at least 0.12 mass %, based on the total mass of the composition, and wherein the borated calcium detergent provides a boron content in the composition of at least 100 ppmm, based on the total mass of the composition. Optionally, the composition comprises a first detergent comprising a calcium detergent, and a second detergent comprising a borated calcium detergent.

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##

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##

A comb polymer can be used for reducing a Noack evaporation loss of a lubricant composition, especially of an engine oil composition. Application of the comb polymer to the lubricant composition can bring about the desired reduction. The comb polymer can include specified amounts of macromonomer and alkyl acrylates. Resulting lubricant compositions can include the comb polymer.

A comb polymer can be used for reducing a Noack evaporation loss of a lubricant composition, especially of an engine oil composition. Application of the comb polymer to the lubricant composition can bring about the desired reduction. The comb polymer can include specified amounts of macromonomer and alkyl acrylates. Resulting lubricant compositions can include the comb polymer.