A method for preventing or reducing engine knock or pre-ignition in a high compression spark ignition engine lubricated with a lubricating oil by introducing to a combustion chamber of the engine from 0.1 to 5% by volume of the gasoline used a lubricating oil as a formulated oil, said formulated oil having a composition comprising (i) a major amount of a lubricating oil base stock comprising at least 80% by weight of one branched ester having at least 15% of the total carbons in the form of methyl groups, and (ii) a minor amount of at least one ashless amine phosphate antiwear additive. Also provided is a lubricating engine oil for high compression spark ignition engines including (i) a major amount of a lubricating oil base stock comprising at least 80% by weight formula I below:

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esterified (per OH basis) with 25 to 100% isobutyric acid and 0 to 75% 3,5,5-trimethylhexanoic acid, wherein R is a H, methyl, ethyl, isopropyl, or isobutyl, and (ii) a minor amount of at least one amine phosphate ashless antiwear additive.

A mixture including a thiophosphoric acid product suitable for preparing organometallic and/or ashless antiwear additives having improved copper corrosion performance. The thiophosphoric acid product is distilled and recovered as a condensate of the distillation and having a low level of active sulfur.

Provided is a mixed grease containing a grease (A) prepared from a base oil (a1) and a thickening agent (a2) that is a lithium soap consisting of a lithium salt of a monovalent fatty acid, and a grease (B) prepared from a base oil (b1) and a thickening agent (b2) that is a lithium complex soap consisting of a lithium salt of a monovalent fatty acid and a lithium salt of a divalent fatty acid. The mixed grease has good wear resistance and load bearing properties and has excellent grease leakage preventing properties.

A lubricating oil composition may be used for lubrication of a shock absorber. The composition may include a base oil (A), a zinc dithiophosphate (B), and an alkenylsuccinic imide (C). The lubricating oil composition can be more preferably applied to lubrication of a shock absorber. Based on the total lubricating oil composition mass, a content of the component (C) in terms of nitrogen atoms is in a range of from 0.001 to 0.09 mass %, and/or a content of the component (B) in terms of zinc atoms is in a range of from 0.005 to 1.0 mass %.

Provided are a lubricating oil composition excellent in anti-seizing properties and ant-wear properties, containing a base oil containing at least a mineral oil and a sulfur- and phosphorus-containing anti-wear agent, a mass ratio (S/P ratio) of a sulfur atom and a phosphorus atom contained in the composition being 7.5 or more and 16 or less; and a lubrication method and a gear each using the same.

A composition obtained by reacting an O,O-dialkyldithiophosphoric acid with a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate, and reacting the product thereof with a dialkylphosphite provides good antiwear protection.

A lubricant composition comprising an oil of lubricating viscosity and about 0.01 to about 5 percent by weight of a (thio)phosphoric acid salt (phos-amine salt) of at least one hydrocarbyl amine. The hydrocarbyl amine may be a hindered hydro-carbyl amine, an aromatic hydrocarbyl amine, or a combination thereof.

The present invention, in one aspect, provides a refrigerating machine oil including a lubricating base oil and a compound represented by the following formula (A):

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wherein R.sup.1 and R.sup.2 each independently represent a monovalent hydrocarbon group, and R.sup.3 and R.sup.4 each independently represent a hydrogen atom or an alkyl group, the refrigerating machine oil being used with a refrigerant including an unsaturated hydrofluorocarbon.

The invention relates to lubricant additive compositions and lubricant compositions each comprising thiophosphates and thiophosphate derivatives, methods for making and using the same, including methods of lubricating machines and machine parts and methods of extending the useful life of elastomeric seal components of such machines.

A lubricating oil composition that can suppress wear of bearings and the like and scoring of gear teeth surfaces and the like even at low viscosity. A lubricating oil composition that includes a lubricating oil base oil, a sulfur-based extreme pressure agent, and a phosphorus-based extreme pressure agent, wherein the lubricating oil composition is characterized in that: the quantity of active sulfur in the sulfur-based extreme pressure agent is 5-30% by mass; the sulfur-based extreme pressure agent is included in the composition at a quantity of 5-15% by mass relative to the mass of the entire lubricating oil composition; and the phosphorus-based extreme pressure agent is included in the composition at a quantity of 1.5-8% by mass relative to the mass of the entire lubricating oil composition.