Lubricating oil composition

A lubricating oil composition comprising:

• (A) a lubricating base oil having a kinematic viscosity of 3 to 20 mm.sup.2 /s at 100.degree. C.,
• (B) an amine salt of molybdic acid represented by the following formula (1):
• ##STR21## wherein R represents a hydrocarbon group having 6 to 15 carbon atoms, (C) is at least one molybdenum compound selected from the group consisting of (i) a molybdenum dithiocarbamate represented by the following formula (2):
• ##STR22## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 each represent a hydrocarbon group having 6 to 15 carbon atoms, and X and Y each represent S or O and (ii) a molybdenum dithiophosphate represented by the following formula (3):
• ##STR23## wherein R.sup.5, R.sup.6, R.sup.7, and R.sup.8 each represent a hydrocarbon group having 6 to 15 carbon atoms, and X and Y each represent S or O, wherein the content of molybdenum from the amine salt of molybdic acid is 200 to 2500 ppm by weight, the content of molybdenum from the molybdenum dithiocarbamate and/or the molybdenum dithiophosphate is 200 to 700 ppm by weight, the total content of molybdenum is 400 to 3,200 ppm by weight, and
• (D) at least one additive selected from the group consisting of a metallic detergent, an ashless dispersant, an antioxidant, an antiwear agent and a viscosity index improver.