Provided is a lubricating oil composition and methods for controlling one or more of foam tendency and foam stability in such composition using as the oil a mixture of at least two base stocks. The at least two base stocks have a surface tension difference between them such that, when the surface tension difference is greater than 1.0 dynes/cm, then one or more of foam tendency and foam stability are enhanced as compared to foam tendency and foam stability achieved using the base stocks separately and not in the mixture. When the surface tension difference between them is less than 1.0 dynes/cm, then one or more of foam tendency and foam stability are reduced or equivalent as compared to foam tendency and foam stability achieved using the base stocks separately and not in the mixture. Two low-foaming base stocks can produce a significant high foam response that reduces or eliminates the need for pro-foaming additives.

A lubricating fluid suitable for use as a shock absorber fluid is disclosed. The lubricating fluid comprises at least 40 wt %, based upon the weight of the lubricating fluid, of a GTL base oil, has a viscosity index in the range of from 50 to 1000, and a pour point of below 30 C.

A lubricating oil composition for automotive transmissions is disclosed. It offers an automotive transmission (especially a fuel-saving type) which satisfies all requirements as regards the properties of resistance to churning, maintenance of the oil film and low-temperature viscosity. It comprises a GTL low viscosity base oil and a Group 1 high viscosity base oil.

The present invention provides a lubricating oil composition comprising: (A) a lubricant base oil including at least one type selected from mineral oil, PAO, and GTL (gas-to-liquid) base oils; (B) a compound having a structure obtained by independently subjecting propylene oxide to addition polymerization with an alcohol or a structure obtained by subjecting a combination of propylene oxide with ethylene oxide and/or butylene oxide to addition polymerization with an alcohol, and being configured so that polyalkylene glycol (PAG) with an oxygen/carbon weight ratio of 0.35 or more and less than 0.45 and/or one or both terminal hydroxyl groups in the polyalkylene glycol (PAG) are blocked; and (C) a fatty acid ester having an oxygen/carbon weight ratio of 0.05 to 0.35.

The invention provides a lubricating oil composition for diesel engines which contains a GTL base oil with a kinematic viscosity at 100 C. of 4.5 to 5.5 mm2/s, a comblike PMA (polymethacrylate) based viscosity index improver and a boron-containing dispersant and/or boron-containing detergent, the total content of the boron-containing dispersant and/or boron-containing detergent in terms of conversion to boron content relative to the total amount of the composition being not less than 0.025 mass %, and which satisfies 0W-30 or 5W-30 in the SAE J300 standard.

The present invention provides a lubricating oil composition for automatic transmissions which comprises: 55 to 85 mass % of a Fischer-Tropsch synthetic oil with a kinematic viscosity at 100 C. of 2 to 4 mm2/s as a low-viscosity base oil; 1 to 10 mass % of an olefin copolymer 5 with a kinematic viscosity at 100 C. of 150 to 1,000 mm2/s as a high-viscosity base oil; and a polymethacrylate with a weight-average molecular weight of 10,000 to 50,000. This lubricating oil composition is such that the viscosity index of the composition is not 10 less than 190, the Brookfield viscosity is not more than 6,000 mPa.Math.s at low temperature (40 C.), the kinematic viscosity at 100 C. is 6 to 7 mm2/s, and the rate of reduction of the kinematic viscosity after a KRL shear stability test (60 C., 20 hr) is kept to within not more 15 than 3%.

A method for improving fuel efficiency and energy efficiency, while maintaining or improving deposit control and cleanliness performance, in an engine lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil includes a base oil mixture. The base oil mixture includes a lubricating oil base stock as a major component, and at least one cobase stock, as a minor component. The at least one cobase stock is present in an amount sufficient to reduce kinematic viscosity (Kv.sub.100) of the base oil mixture as determined by ASTM D445, while maintaining or controlling cold cranking simulator viscosity (CCSV) of the lubricating oil as determined by ASTM D5293-15, such that the lubricating oil meets both kinematic viscosity (Kv.sub.100) and cold cranking simulator viscosity (CCSV) requirements for a SAE engine oil grade as determined by SAE J300 viscosity grade classification system. A lubricating oil having a composition including a lubricating oil base stock as a major component, and at least one cobase stock, as a minor component.

The invention relates to a seal swell agent which is a substituted sulfonyldibenzene compound, and lubricating compositions containing the seal swell agent. The substituents on the benzene rings may be hydrocarbyl groups of 4 to 20 carbon atoms or alkylene groups of 1-2 carbon atoms with further functional groups.

A lubricating oil composition for automotive transmissions is disclosed. It offers an automotive transmission (especially a fuel-saving type) which satisfies all requirements as regards the properties of resistance to churning, maintenance of the oil film and low-temperature viscosity. It comprises a GTL low viscosity base oil and a Group 1 high viscosity base oil.

An industrial lubricant composition including an oil base selected from the group consisting of vegetable oil, Group I, Group II, Group III, Group IV, Group V and combinations thereof and a phosphorus-based non-chlorine additive. The industrial lubricant also includes at least one intercalation compound of a metal chalcogenide, a carbon containing compound and a boron containing compound, wherein the intercalation compound may have a geometry that is a platelet shaped geometry, a spherical shaped geometry, a multi-layered fullerene-like geometry, a tubular-like geometry or a combination thereof.