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.

The present invention relates to provision of an extreme pressure agent-containing grease composition using, as a thickener, a urea-based thickener, the grease composition being excellent in both torque transmitting efficiency and leakage prevention performance and also excellent in wear resistance and load resistance. The grease composition contains a base oil (A), a urea-based thickener (B), and an extreme pressure agent (C), wherein particles containing the urea-based thickener (B) in the grease composition satisfies the following requirement (I): Requirement (I): an arithmetic average particle diameter of the particles on an area basis as measured by the laser diffraction/scattering method is 2.0 μm or less, and the extreme pressure agent (C) is at least one selected from an organic metal-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a sulfur-phosphorus-based extreme pressure agent.

The present invention relates to provision of an extreme pressure agent-containing grease composition using, as a thickener, a urea-based thickener, the grease composition being excellent in both torque transmitting efficiency and leakage prevention performance and also excellent in wear resistance and load resistance. The grease composition contains a base oil (A), a urea-based thickener (B), and an extreme pressure agent (C), wherein particles containing the urea-based thickener (B) in the grease composition satisfies the following requirement (I): Requirement (I): an arithmetic average particle diameter of the particles on an area basis as measured by the laser diffraction/scattering method is 2.0 μm or less, and the extreme pressure agent (C) is at least one selected from an organic metal-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a sulfur-phosphorus-based extreme pressure agent.

The present invention relates to the use of at least one diester having formula (I) in a lubricant composition containing at least one base oil, so as to increase the oxidation resistance of said lubricant composition or to decrease the oxidation level of said lubricant composition,

R.sup.a—C(O)—O—([C(R).sub.2].sub.n—O).sub.s—C(O)—R.sup.b   (I)

The present invention relates to the use of at least one diester having formula (I) in a lubricant composition containing at least one base oil, so as to increase the oxidation resistance of said lubricant composition or to decrease the oxidation level of said lubricant composition,

R.sup.a—C(O)—O—([C(R).sub.2].sub.n—O).sub.s—C(O)—R.sup.b   (I)

A transmission fluid composition contains a major amount of a lubricating oil basestock, and a minor amount of an additive package comprising: (i) a mixture comprising two or more phosphites and/or phosphates; (ii) one or more thioester compounds; (iii) one or more zinc dihydrocarbyl dithiophosphate compounds; and (iv) one or more oil-soluble or dispersible molybdenum-containing compounds. Such a transmission fluid may be used for controlling and/or reducing wear, e.g., in a manual transmission.

A transmission fluid composition contains a major amount of a lubricating oil basestock, and a minor amount of an additive package comprising: (i) a mixture comprising two or more phosphites and/or phosphates; (ii) one or more thioester compounds; (iii) one or more zinc dihydrocarbyl dithiophosphate compounds; and (iv) one or more oil-soluble or dispersible molybdenum-containing compounds. Such a transmission fluid may be used for controlling and/or reducing wear, e.g., in a manual transmission.

The present invention relates to the use of a lubricant composition comprising (i) at least one dithiocarbamate compound; and (ii) at least one base oil, for preventing and/or reducing pre-ignition, in particular at low speed, in a vehicle engine, wherein said composition is applied during at least one change interval without the addition of a new lubricant composition, the content of dithiocarbamate compound being less than or equal to 1% by weight relative to the total weight of the lubricant composition.

The present invention relates to the use of a lubricant composition comprising (i) at least one dithiocarbamate compound; and (ii) at least one base oil, for preventing and/or reducing pre-ignition, in particular at low speed, in a vehicle engine, wherein said composition is applied during at least one change interval without the addition of a new lubricant composition, the content of dithiocarbamate compound being less than or equal to 1% by weight relative to the total weight of the lubricant composition.