The invention provides a lubricant composition comprising an oil of lubricating viscosity and a (thio)phosphoric acid salt of an N-hydrocarbyl-substituted gamma- (-) or delta- (-)amino(thio)ester. The invention further relates to a method of lubricating a mechanical device with the lubricant composition.

Provided are a lubricating oil composition containing (A) a specific amide compound and (B) a metal-based detergent, wherein the content of the metal-based detergent (B) as converted in terms of metal atom is, based on the total amount of the composition, more than 300 ppm by mass and 1,000 ppm by mass or less, and having a high intermetallic friction coefficient and excellent clutch anti-shudder performance; and a lubrication method and a transmission using the composition.

The invention provides a lubricant composition comprising an oil of lubricating viscosity and 0.01 wt % to 15 wt % of a protic acid salt of an N-hydrocarbyl-substituted gamma- (-) or delta- (-)amino(thio)ester. The invention further relates to a method of lubricating a mechanical device with the lubricant composition.

Provided are a lubricating oil composition containing a component (A): a succinimide having an alkenyl group or an alkyl group, a component (B): a primary amine having a hydrocarbon group having 12 or more and 24 or less carbon atoms, a component (C): a fatty acid amide compound, and a component (D): an amide compound having a specific structure, and capable of satisfying both a high clutch capacity and a long anti-shudder lifetime; and a lubrication method and a transmission using the composition.

A lubricating oil composition having a sulphated ash content of less than or equal to 1.2 mass % as determined by ASTM D874 and a phosphorous content of less than or equal to 0.12 mass % as determined by ASTM D5185, which lubricating oil composition comprises or is made by admixing: an oil of lubricating viscosity, in a major amount; an oil-soluble or oil-dispersible polymeric friction modifier as an additive in an effective minor amount; and, at least one oil-soluble or oil-dispersible molybdenum compound as an additive in an effective minor amount.

A lubricating oil composition having a sulphated ash content of less than or equal to 1.2 mass % as determined by ASTM D874 and a phosphorous content of less than or equal to 0.12 mass % as determined by ASTM D5185, which lubricating oil composition comprises or is made by admixing: an oil of lubricating viscosity, in a major amount; an oil-soluble or oil-dispersible polymeric friction modifier as an additive in an effective minor amount; and, at least one oil-soluble or oil-dispersible molybdenum compound as an additive in an effective minor amount.

An automatic transmission fluid comprises a major amount of an oil of lubricating viscosity and minor amounts of (a) one or more oil-soluble or dispersible molybdenum-containing compounds, and (b) a reaction product of an isomerized alkenyl-substituted succinic anhydride and a polyamine characterized by structure (II):

##STR00001##

In structure (II) x and y are independently zero or integers from 1 to 30, where x+y is from 1 to 30, and z is zero or an integer from 1 to 10.

An automatic transmission fluid comprises a major amount of an oil of lubricating viscosity and minor amounts of (a) one or more oil-soluble or dispersible molybdenum-containing compounds, and (b) a reaction product of an isomerized alkenyl-substituted succinic anhydride and a polyamine characterized by structure (II):

##STR00001##

In structure (II) x and y are independently zero or integers from 1 to 30, where x+y is from 1 to 30, and z is zero or an integer from 1 to 10.

A method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine comprising lubricating the crankcase of the engine with a composition comprising a combination of a molybdenum-containing additive and a boron-containing additive. Preferably, the composition comprises a calcium detergent providing a calcium content of at least 0.08 wt %, based on the weight of the lubricating oil composition.

A method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine comprising lubricating the crankcase of the engine with a composition comprising a combination of a molybdenum-containing additive and a boron-containing additive. Preferably, the composition comprises a calcium detergent providing a calcium content of at least 0.08 wt %, based on the weight of the lubricating oil composition.