Lubricant composition

A lubricant composition comprising:

• (A-1) a Fischer-Tropsch-derived base oil having a kinematic viscosity at 100° C. of 6 to 9 mm2/s;
• (A-2) a poly-alpha-olefin having a kinematic viscosity at 100° C. of 30 to 50 mm2/s;
• and (A-3) an ester compound having a kinematic viscosity at 100° C. of 3 to 6 mm2/s, and further comprising (B-1) an unsaturated fatty acid and/or (B-2) a partial ester compound of an unsaturated fatty acid and a polyol, wherein the partial ester compound of an unsaturated fatty acid and a polyol includes a monoester compound of an unsaturated fatty acid and a polyol at a proportion of 50% by mass or more of the total amount of the partial ester compound, and the SAE viscosity grade is 75W-85 or lower,
• wherein the (B-2) partial ester compound of an unsaturated fatty acid and a polyol is a partial ester of an unsaturated fatty acid and pentaerythritol, a partial ester of an unsaturated fatty acid and trimethylolpropane, or a partial ester of an unsaturated fatty acid and glycerol, or a combination of these esters,
• wherein the (B-1) unsaturated fatty acid and/or the (B-2) partial ester compound of an unsaturated fatty acid and a polyol at a proportion of 0.2 to 2% by mass in total with respect to the total mass of the composition,
• wherein the (A-1) Fischer-Tropsch-derived base oil is at a proportion of 50 to 60% by mass with respect to the total mass of the composition, the (A-2) poly-alpha-olefin is at a proportion of 15 to 25% by mass with respect to the total mass of the composition, and the (A-3) ester compound is at a proportion of 8 to 12% by mass with respect to the total mass of the composition,
• wherein the (A-3) ester compound is an ester compound of trimethylolpropane, a linear carboxylic acid having 8 carbon atoms, and a linear carboxylic acid having 10 carbon atoms, and
• wherein the unsaturated fatty acid is selected from the group consisting of palmitoleic acid, oleic acid, elaidic acid, gadoleic acid, and eicosenoic acid.