The present patent application relates to a method for reducing wear and tear on mechanical parts that are in contact with each other in an internal combustion engine by using a lubricating composition comprising: at least one base oil; at least one oxothiomolybdate salt; and at least one anti-wear compound;
wherein at least one of the said parts includes a surface that comprises an amorphous carbon type coating.

The present patent application relates to a method for reducing wear and tear on mechanical parts that are in contact with each other in an internal combustion engine by using a lubricating composition comprising: at least one base oil; at least one oxothiomolybdate salt; and at least one anti-wear compound;
wherein at least one of the said parts includes a surface that comprises an amorphous carbon type coating.

The refrigerator lubricating oil of the present invention contains: a base oil containing, as a major component, a polyol ester (A) of a fatty acid (a1) that is a fatty acid having a number of carbon atoms of from 3 to 18 and a polyol (a2) that is selected from neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, and dipentaerythritol; and a disulfide and/or trisulfide compound (B), and the disulfide and/or trisulfide compound (B) is blended in an amount of from 30 to 10,000 ppm by mass in terms of sulfur equivalent based on the total amount of the refrigerator lubricating oil.

A lubricating oil composition for transmissions is provided which improves fuel saving properties and has excellent metal fatigue life and heat resistance. The composition contains 50 to 97 percent by mass of (A) a mineral base oil having a 100 C. kinematic viscosity of 1.5 mm.sup.2/s or higher and 3.5 mm.sup.2/s or lower, a pour point a 25 C. or lower, a viscosity index of 105 or greater, a % C.sub.p of 85 or greater, a % C.sub.N of 2 or greater and 20 or less and a % C.sub.A of 3 or less; 3 to 10 percent by mass of (B) a monoester-hased base oil having a 100 C. kinematic viscosity of 2 mm.sup.2/s or higher and 10 mm.sup.2/s or lower; and 150 to 400 ppm by mass as phosphorus of (C) a specific sulfur-containing phosphite ester. The composition has a 100 C. kinematic viscosity of 2.5 mm.sup.2/s or higher and 4.0 mm.sup.2/s or lower.

A lubricating oil composition for transmissions is provided which improves fuel saving properties and has excellent metal fatigue life and heat resistance. The composition contains 50 to 97 percent by mass of (A) a mineral base oil having a 100 C. kinematic viscosity of 1.5 mm.sup.2/s or higher and 3.5 mm.sup.2/s or lower, a pour point a 25 C. or lower, a viscosity index of 105 or greater, a % C.sub.p of 85 or greater, a % C.sub.N of 2 or greater and 20 or less and a % C.sub.A of 3 or less; 3 to 10 percent by mass of (B) a monoester-hased base oil having a 100 C. kinematic viscosity of 2 mm.sup.2/s or higher and 10 mm.sup.2/s or lower; and 150 to 400 ppm by mass as phosphorus of (C) a specific sulfur-containing phosphite ester. The composition has a 100 C. kinematic viscosity of 2.5 mm.sup.2/s or higher and 4.0 mm.sup.2/s or lower.