| abstract |
A final-drive lubricating oil composition comprising a base oil and, added thereto, (A) 0.1-5 wt.% of a phosphoric ester, a phosphorous ester or an alkylamine salt of a phosphoric ester, (B) 0.1-5 wt.% of an organic acid represented by the general formula: R¹-CON(CH₃)CH₂COOH (wherein R¹ represents C₁-C₁₈ alkyl or C₂-C₁₈ alkenyl) and (C) 3-15 wt.% of a sulfurized olefin or an alkyl sulfide, each based on the whole composition. The composition serves to further improve the transmission efficiency at the differential gear under varied conditions of input torque, input rotational speed and oil temperature as compared with the conventional compositions containing additives based on sulfur and phosphorous compounds, thus leading to fuel consumption improvement. |