A crankcase lubricating oil composition for the crankcase of a spark-ignited or compression-ignited internal combustion engine, comprising a magnesium-containing detergent, in an amount sufficient to provide from 200-4000 ppm magnesium to the lubricating oil composition, in combination with an oil-soluble or oil-dispersible molybdenum compound in an amount sufficient to provide from 600-1500 ppm molybdenum atoms to the lubricating oil composition, and with an oil-soluble or oil-dispersible boron-containing compound in an amount sufficient to provide from 200-600 ppm boron atoms to the lubricating oil composition to improve the friction and fuel economy performance.

A lubricating composition suited to use in lubricating an internal combustion engine includes an oil of lubricating viscosity and a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or metal salt thereof, wherein the polyolefin is derived from a isobutylene having a number average molecular weight of 150 to 800.

Disclosed herein is a process for preparing a sulfurized non-overbased calcium phenate detergent having a reduced content of un-sulfurized alkyl-substituted phenol and its salt. The process steps involve adding an organic solvent to the detergent, wherein the organic solvent has a boiling point of equal or above the boiling point of the un-sulfurized alkyl-substituted phenol. Distilling the organic solvent from the detergent to reduce the content of the un-sulfurized alkyl-substituted phenol.

Disclosed herein is a process for preparing a sulfurized non-overbased calcium phenate detergent having a reduced content of un-sulfurized alkyl-substituted phenol and its salt. The process steps involve adding an organic solvent to the detergent, wherein the organic solvent has a boiling point of equal or above the boiling point of the un-sulfurized alkyl-substituted phenol. Distilling the organic solvent from the detergent to reduce the content of the un-sulfurized alkyl-substituted phenol.

A lubricating composition includes a sulfurized oxy-substituted aromatic polyol compound and an oil of lubricating viscosity. The sulfurized oxy-substituted aromatic polyol compound includes at least one of a sulfurized oxy-substituted aromatic polyol and a salt of a sulfurized oxy-substituted aromatic polyol. The compound is suitable as a replacement for detergents that contain C.sub.n alkyl phenols derived from oligomers of propylene.

A lubricating composition includes an oil of lubricating viscosity and a compound comprising a protected mercaptophenol. The protected mercaptophenol includes a mercapto group in which the hydrogen is substituted with a substituent of at least 5 carbons. The substituent is selected from hydroxy-substituted hydrocarbyl groups, poly(ether) groups, hydrocarbyl groups, and mixtures and salts thereof.

The invention provides a method of lubricating a 2-stroke marine diesel cylinder liner with a lubricating composition having a total base number of 10 to 25 mg KOH/g. The invention further provides a lubricating composition for lubricating the 2-stroke marine diesel cylinder liner.

The invention provides a method of lubricating a 2-stroke marine diesel cylinder liner with a lubricating composition having a total base number of 10 to 25 mg KOH/g. The invention further provides a lubricating composition for lubricating the 2-stroke marine diesel cylinder liner.

The disclosed technology provides alkylphenol-containing detergent having at least one unit (a) of an alkyl-substituted phenol wherein the alkyl group is derived from oligomers of an olefin compound containing 3 to 8 carbon atoms, wherein the polyolefin-derived alkyl group comprises at least 30 mol percent of an olefin with 4 or more carbon atoms. The invention further relates to a method of lubricating a mechanical device with the lubricant composition.

Provided herein are compositions that include a thiadiazole component and a solubility enhancing component. The solubility enhancing component can include a dispersant, a detergent, or both a dispersant and a detergent. The thiadiazole component can include one or more species having a hydrocarbyl-disulfanyl moiety. The compositions may be used as a corrosion inhibitor. Also provided herein are methods for making a thiadiazole component and a composition.