A lubricating oil composition including greater than 50 wt. % of a base oil, from 100 ppm to less than 1800 ppm by weight of total metal from metal-containing detergent(s) including an overbased calcium detergent and a magnesium containing detergent. The composition has a total nitrogen of 900 ppm to less than 1600 ppm by weight, and a ratio of total metal from the detergent(s) in ppm to the total nitrogen in ppm of less than 1.9. The composition also includes a borated compound to provide greater than 50 ppm by weight to 1000 ppm by weight of boron, and a ppm ratio of metal from the detergent(s) in ppm to the total boron is less than 7.5 and a molybdenum compound to provide greater than 80 ppm to 1200 ppm by weight molybdenum and a ppm ratio of total metal from the detergent(s) to the molybdenum is less than 23.8.

A sliding member has a sliding surface sliding under a wet condition in which a lubricant oil exists. The sliding surface is coated with a laminate film comprising an upper layer and a lower layer. The lower layer comprises hydrogen-free amorphous carbon (hydrogen-free DLC) and carbon particles dispersed on or in the hydrogen-free DLC. The hydrogen-free DLC has a hydrogen content of 5 atom % or less when the lower layer as a whole is 100 atom %. The upper layer comprises boron-containing amorphous carbon (B-DLC) and has protrusions on a surface side of the upper layer along the carbon particles of the lower layer. The B-DLC has a boron content of 1-40 atom % when the upper layer as a whole is 100 atom %. The protrusions have a particle diameter of 0.5-5 m and exist with a density of 20 protrusions/100 m.sup.2 or more.

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The present invention provides a lubricant composition for an internal combustion engine comprising a base oil of lubricating viscosity, wherein the base oil comprises an ether base stock of formula (A): where: R.sub.a and R.sub.b are aliphatic hydrocarbyl groups and may be the same or different; wherein at least one of R.sub.a and R.sub.b is branched-chain alkyl, alkoxy-substituted-alkyl or cycloalkyl-substituted-alkyl; the lubricant composition further comprising: i) at least one molybdenum compound as a lubricant additive which is present, on a molybdenum element basis, in an amount of at least 0.06% by weight of the lubricant composition; or ii) at least one polymethacrylate compound as a lubricant additive which is present in an amount of from 0.1 to 7.5% by weight of the lubricant composition. The lubricant composition may be used for lubricating a surface in an internal combustion engine as well as for improving the fuel economy performance and/or piston cleanliness performance and/or turbocharger cleanliness performance of an engine and/or a vehicle, such as an automotive vehicle associated with an internal combustion engine.

The present invention is directed to a use of a lubricant in a diesel engine to disperse soot produced by the diesel engine, the soot being dispersed without adversely affecting the viscosity of the lubricant; the lubricant comprising a major amount of oil of lubricating viscosity and a minor amount of a dispersant comprising (i) one or more olefin, (ii) one or more carboxylic acid, (iii) one or more polyetheramines and (iv) one or more aromatic amines along with co-additives.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition is formulated to be resistant to turbocharger deposit formation in the boosted internal combustion engine, as shown by its ability to ensure a TCO Temperature Increase of less than 9.0% as measured using the 2015 version of the General Motors Dexos1 Turbocharger Coking Test. The lubricating oil composition may also have a low NOACK volatility, as measured by the method of ASTM D-5800 at 250 C.

To provide a lubricating oil composition that has good detergency irrespective of the small sulfated ash content thereof, and has a good friction reducing capability even after the deterioration thereof. The lubricating oil composition contains a base oil (A), a non-metal-containing sulfur antioxidant (B), and a hindered amine antioxidant (C) having one piperidine-derived skeleton in a molecule, and has a content of the non-metal-containing sulfur antioxidant (B) as converted in terms of sulfur atom of 800 ppm by mass or more based on the total amount of the lubricating oil composition, a content of the hindered amine antioxidant (C) as converted in terms of nitrogen atom of 100 ppm by mass or more and 400 ppm by mass or less based on the total amount of the lubricating oil composition, a sulfated ash content of 0.70% by mass or less, and a total base number of 4.0 mgKOH/g or more.

The present disclosure generally relates to a lubricating oil composition having a sulfur content of up to 0.4 wt. % and a sulfated ash content of up to 0.6 wt. %, as determined by ASTM D874, comprising: a major amount of base oil; at least 0.02 wt. % of triazole compound; less than about 1.3 wt. % of a diphenylamine antioxidant; and at least 900 ppm of molybdenum from a molybdenum containing compound; wherein the lubricating oil composition is essentially free of ZnDTP. Also provided are methods for reducing wear and copper corrosion in an engine which is equipped with a diesel particulate filter (DPF) or a gasoline particulate filter (GPF) after treatment device system.

Methods are provided for lubricating oxygenated diamond-like carbon surfaces to reduce friction while reducing or minimizing wear on the surface. A diamond-like carbon surface layer having a surface ratio of oxygen to carbon of 1:15 or more can be lubricated using a lubricant oil that includes a molybdenum-based friction modifier additive, a tungsten-based friction modifier additive, or a combination thereof. The Mo-based friction modifier (and/or other friction modifier based on a Group VI metal) can be selected based on the Gibbs free energy of adsorption (G) for the friction modifier on an oxygenated diamond-like carbon surface. Use of a Group VI metal-based friction modifier having a G of adsorption with a sufficiently large magnitude can reduce friction at the surface of the oxygenated diamond-like carbon while causing a reduced or minimized amount of wear during lubrication.

A method for extending performance or service life of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and at least one microencapsulated lubricating oil additive, as a minor component. The at least one microencapsulated lubricating oil additive includes an encapsulating material (e.g., polymeric matrix) and a core material (e.g., at least one lubricating oil additive) encapsulated by the encapsulating material. A method of improving solubility, compatibility and/or dispersion of lubricating oil additives in a lubricating oil base stock. A method for controlling release of a lubricating oil additive into a lubricating oil. A lubricating oil having a composition including a lubricating oil base stock as a major component, and at least one microencapsulated lubricating oil additive, as a minor component.

A lubricant composition including a binuclear molybdenum compound (A) and a trinuclear molybdenum compound (B), wherein these compounds are included in a range represented by (molybdenum of the binuclear molybdenum compound (A)):(molybdenum of the trinuclear molybdenum compound (B))=99.98:0.02 to 95:5 as a mass ratio.