A lubricating oil composition including: a lubricating base oil; (A) a first defoaming agent, the first defoaming agent being (A1) a first polymer, or (A2) a second polymer, or any combination thereof; and (B) a second defoaming agent, the second defoaming agent being a silicone defoaming agent, the (A1) first polymer including: a first polymer chain including a polysiloxane structure, the polysiloxane structure having a polymerization degree of 5 to 2000 and being represented by the following general formula (1); and a second polymer chain bonded with the first polymer chain, the second polymer chain including a repeating unit represented by the following general formula (2), the (A2) second polymer being a copolymer of a first monomer component and a second monomer component, the first monomer component represented by the general formula (7) or (8), the second monomer component represented by the general formula (9). ##STR00001##

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) a detergent comprising calcium salicylate; and (iv) a poly(alkylene amine)-based ashless dispersant endcapped with metallocene-catalyzed PAO arms. Such a transmission fluid may be used for controlling/reducing wear in at least partially electrically-powered transmissions and/or for cooling/insulating electrical/electronic components of at least partially electrically-powered drivetrains.

A lubricant composition of an oil of lubricating viscosity, a grafted copolymer viscosity modifier that is an ashless condensation reaction product of an olefin polymer, having a number average molecular weight of about 1000 to about 10,000, comprising carboxylic acid or equivalent functionality grafted onto the polymer backbone, with a monoamine or a polyamine often having a single primary amino group, which exhibits good dispersancy and viscometric performance in a driveline device.

The instant disclosure relates to hydrocarbyl- (e.g., alkyl-) benzene sulfonate detergents and their salts, where the hydrocarbyl group includes moieties equivalent to 5 to 10 carbon branched polyene compounds. Such compounds and their salts are useful as lubricant additives. The detergents disclosed herein may solve at least one problem of providing anti-wear performance, frictional performance, oxidation performance, viscosity performance, and detergency.

The present disclosure relates to an anti-wear, anti-friction and stably-dispersed lubricating oil or grease, and the anti-wear, anti-friction and stably-dispersed lubricating oil or grease includes a main component of a lubricating oil or grease and a long carbon chain-grafted sulfonated graphene, the preparation method of which includes mixing a main component of a lubricating oil or grease with a long carbon chain-grafted sulfonated graphene, stirring and dispersing the mixture to obtain the product. The lubricating oil or grease in the present disclosure can significantly improve the long-term dispersion stability and dispersion stability in a complex environment by adding a long carbon chain-grafted sulfonated graphene in the main component, and at the same time can significantly improve the friction coefficient, which can significantly improve the anti-wear and anti-friction properties of the lubricating oil or grease, reduce the diameter of wear scars, and reduce the wear of copper and iron.

A composition comprising an oil of lubricating viscosity and a compound represented by formula (I) wherein: x is 0 or 1; R.sup.1 is a hydrocarbyl group containing about 4 or about 18 carbon atoms; R.sup.2 is an aliphatic hydrocarbyl group containing about 1 to about 12 carbon atoms; and y is 0 or 1, which composition is effective at swelling seals. ##STR00001##

The present disclosure relates to a lubricant composition comprising a first phosphorus compound, a second phosphorus compound, and a third phosphorus compound, wherein the first phosphorus compound is present in the lubricant composition in an amount to provide between about 120 and 350 ppm phosphorus. The lubricant composition may provide robust anti-wear and reduced pitting.

The present invention is directed to the use of poly(polyisobutylenemethacrylate) as viscosity index improving component in lubricating oil compositions. The invention is further related to lubricating oil compositions comprising poly(polyisobutylenemethacrylate) with enhanced shear stability.

A multi-functional olefin copolymer viscosity index improver and a lubricating oil composition including such lubricant additive that provides improved viscometric properties and helps reduce low speed pre-ignition events at the same time. In one approach, the multi-functional olefin copolymer viscosity index improver is silicone functionalized and includes an acylated olefin copolymer with aminosilane or aminosiloxone pendant or side groups.

This invention provides a lubricating oil composition for automobile transmission that includes: as low-viscosity base oils: (i) between 45 and 95 mass % of a Fischer-Tropsch synthetic low-viscosity base oil with a 100° C. kinematic viscosity of between 1 mm.sup.2/s and 2 mm.sup.2/s, and between 0 and 25 mass % of other than a Fischer-Tropsch synthetic low-viscosity base oil with a 100° C. kinematic viscosity of between 1 mm.sup.2/s and 2 mm.sup.2/s, and (ii) between 0 and 35 mass % of a base oil wherein the 100° C. kinematic viscosity is greater that 2 mm.sup.2/s and no greater than 5 mm.sup.2/s; and (iii) between 5 and 55 mass % of an olefin polymer or copolymer, as a high-viscosity base oil, wherein the 100° C. kinematic viscosity is between 100 and 800 mm.sup.2/s. A lubricating oil composition for an automatic transmission wherein the 100° C. kinematic viscosity of this composition is between 3.8 and 5.5 mm.sup.2/s, the viscosity index is no less than 190, the flashpoint is no less than 140° C., and the reduction ratio of the 100° C. kinematic viscosity after shear stability testing, at 60° C. for 20 hours, is maintained at no greater than 3%.