The object of the present invention is to provide a foreign substance removing lubricant composition having high foreign substance removing effects and being capable of improving the lubricating properties as compared to conventional lubricant compositions, a foreign substance removing lubricant composition applied member, and a method for using the foreign substance removing lubricant composition. The foreign substance removing lubricant composition of the present invention comprises a perfluoroalkyl group containing compound (S) having a perfluoroalkyl group or a fluoropolyether containing compound. As a result, foreign substance removing effects can be enhanced, and the lubricating properties can be improved as compared to the conventional lubricant compositions.

The object of the present invention is to provide a foreign substance removing lubricant composition having high foreign substance removing effects and being capable of improving the lubricating properties as compared to conventional lubricant compositions, a foreign substance removing lubricant composition applied member, and a method for using the foreign substance removing lubricant composition. The foreign substance removing lubricant composition of the present invention comprises a perfluoroalkyl group containing compound (S) having a perfluoroalkyl group or a fluoropolyether containing compound. As a result, foreign substance removing effects can be enhanced, and the lubricating properties can be improved as compared to the conventional lubricant compositions.

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.

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.

Provided are a lubricating oil composition containing a synthetic oil (1) having a kinematic viscosity at 100 C. of 2.5 mm.sup.2/s or less, and a polymethacrylate (2) having a monovalent functional group containing an oxygen atom in the molecule while having a specific structural unit, which satisfies both high viscosity index and high shear stability, and a lubrication method and a transmission using the lubricating oil composition.

Provided are a lubricating oil composition containing a synthetic oil (1) having a kinematic viscosity at 100 C. of 2.5 mm.sup.2/s or less, and a polymethacrylate (2) having a monovalent functional group containing an oxygen atom in the molecule while having a specific structural unit, which satisfies both high viscosity index and high shear stability, and a lubrication method and a transmission using the lubricating oil composition.

Provided is a lubricating oil composition for electric vehicle or hybrid vehicle having excellent gear properties, clutch properties, cooling properties, and electric insulating properties. The lubricating oil composition for electric vehicle or hybrid vehicle preparing by blending (A) a base oi and (B-1) a polyamide and/or (B-2) a polyol ester, the base oil (A) including (A-1) a synthetic oil having a kinematic viscosity at 100 C. of 1.0 to 10.0 mm.sup.2/s.

Provided is a lubricating oil composition for electric vehicle or hybrid vehicle having excellent gear properties, clutch properties, cooling properties, and electric insulating properties. The lubricating oil composition for electric vehicle or hybrid vehicle preparing by blending (A) a base oi and (B-1) a polyamide and/or (B-2) a polyol ester, the base oil (A) including (A-1) a synthetic oil having a kinematic viscosity at 100 C. of 1.0 to 10.0 mm.sup.2/s.

The present disclosure describes a lubricating composition including a) a major part of a base oil of lubricating viscosity wherein the base oil is selected from API Group I, II, III, IV, V, or mixtures thereof, b) a total of 0.001 to 0.536 wt. %, based on the total lubricating composition, of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivative(s) according to Formula (I), or a tautomer or salt thereof, below ##STR00001## wherein R is methyl or C.sub.2 to C.sub.4 alkyl, wherein the total lubricating composition has a sulfur content of up to 2,500 ppm (wt.), c) less than 0.1 wt % phosphite. The disclosure further describes the use of the lubricating composition for lubricating a driveline, a transmission including a manual or automated transmission, a gear, an automated gear, or an axle, and for enhanced FZG test performance. The disclosure further relates to a method for preparing the lubricating composition.

The present disclosure describes a lubricating composition including a) a major part of a base oil of lubricating viscosity wherein the base oil is selected from API Group I, II, III, IV, V, or mixtures thereof, b) a total of 0.001 to 0.536 wt. %, based on the total lubricating composition, of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivative(s) according to Formula (I), or a tautomer or salt thereof, below ##STR00001## wherein R is methyl or C.sub.2 to C.sub.4 alkyl, wherein the total lubricating composition has a sulfur content of up to 2,500 ppm (wt.), c) less than 0.1 wt % phosphite. The disclosure further describes the use of the lubricating composition for lubricating a driveline, a transmission including a manual or automated transmission, a gear, an automated gear, or an axle, and for enhanced FZG test performance. The disclosure further relates to a method for preparing the lubricating composition.