The disclosed technology relates to a lubricant composition for automotive or industrial gears, as well as axles and bearings, the automotive or industrial gear oil containing an oil of lubricating viscosity, an optional phosphate and/or thiophosphate compound, a particular sulfurized olefin, either a metal thiophosphate compound, such as zinc dialkyldithiophosphate, a thiadiazole functionalized dispersant, or a mixture thereof, and a hydroxyl/amine containing booster, as well as a method of improving automotive or industrial gear operating efficiency and temperature by lubricating such automotive or industrial gears with the automotive or industrial gear oil.

A lubricating oil composition is described. The composition includes a base oil, a first succinimide dispersant composition comprising a reaction product of a hydrocarbyl succinimide and an aromatic glycidyl ether having a structure: ##STR00001##
wherein R.sub.1 is an aryl or alkaryl group having 4 to 20 carbon atoms, and R.sub.2 and R.sub.3 are independently a hydrogen atom, an alkyl group, or an aryl group; and a second succinimide dispersant.

A lubricating oil composition contains a base oil (A), a zinc dithiophosphate (B), and a sarcosine compound (C), the composition having a content of the sarcosine compound (C) of more than 0.05% by mass and 0.40% by mass or less based on the entire amount of the lubricating oil composition, and satisfying requirement () or (): Requirement (): when the content of the sarcosine compound (C) is more than 0.05% by mass and less than 0.20% by mass based on the lubricating oil composition, one or more phosphorus compounds (D) selected from an acidic phosphoric acid ester (D1) and an amine salt thereof (D2) are optionally contained; Requirement (): when the content of the sarcosine compound (C) is 0.20% to 0.40% by mass based on the lubricating oil composition, the phosphorus compound (D) is contained in an amount less than 0.50% by mass based on the lubricating oil composition.

The present patent application relates to the use of non fluorinated aromatic polymers as additives for fluorinated lubricants.

A method of producing a lube base oil mixture includes providing a waste lubricant-derived refined oil fraction derived from a waste lubricant containing a lube base oil of API Group I or II. The waste lubricant-derived refined oil fraction contains an ionic refined oil, a first regenerated base oil, or a combination thereof, dewaxing the waste lubricant-derived refined oil fraction to produce a second regenerated base oil, and blending the second regenerated base oil with a separate lube base oil to produce a lube base oil mixture of Group III or higher. The method has an economical advantage because low-quality waste lubricant is used as a feedstock for the production of higher quality lube base oils. In addition, the method is advantageous in an environmentally friendly aspect because waste lubricant is reused rather than being disposed of.