Lubricant composition for automatic transmission

摘要

The invention provides a lubricant composition for automatic transmissions excellent in sustainability of anti-shudder property, low-temperature viscosity characteristics, and oxidation stability, and excellent and well-balanced in durability of friction characteristics, energy-conserving performance, and anti-fatigue performance on gears. The composition contains a base oil having a kinematic viscosity at 100 °C of 3.7-4.1 mm 2 /s, and composed of base oil having the viscosityof 2.5-4.5 mm 2 /s, and base oil having the viscosity of 10-40 mm 2 /s; 1-20 mass% poly(meth)acrylate viscosity index improver having Mw of 15000-30000; 2-4 mass% imide friction modifier having a C8-C30 hydrocarbon group; 0.01-0.04 mass% phosphorus extreme pressure agent in terms of phosphorus; and 0.01-0.04 mass% ashless dispersant having at least one alkyl or alkenyl group of a number average molecular weight of ‰¥2000 in terms of nitrogen, all with respect to the total amount of the composition, and has the viscosity of 5.6-5.8 mm 2 /s.