A lubricating oil composition which comprises (A) a base oil, (B) calcium salicylate having a base number of 50 to 300 mgKOH/g in an amount of 0.005 to 0.07 percent by mass in terms of calcium, (C) an SP type extreme pressure additive in an amount of 0.005 to 0.07 percent by mass in terms of phosphorous, (D) a specific succinimide compound in an amount of 0.1 to 6 percent by mass, and (E) a boron-containing ashless dispersant in an amount of 0.001 to 0.05 percent by mass in terms of boron, based on the total mass of the composition. The lubricating oil composition can prevent pitching of a transmission, resulting in the extended fatigue life thereof, and exhibits excellent and long-lasting anti-shudder properties.
A transmission fluid composition for automobiles comprises a lubricating base oil, (A) an oil-soluble metal salt overbased with a specific alkaline earth metal borate, and (B) a sulfur-containing extreme pressure additive. The transmission fluid can enhance a metallic friction coefficient, leading to the achievement of improved transmission torque.