The present invention relates to a lubricating oil composition having improved fuel saving properties and also having excellent metal fatigue prevention properties and heat resistance and thus provides a lubricating oil composition for transmissions comprising: a lubricating base oil comprising (A) a mineral base oil having a 100°C kinematic viscosity of 1. 5 mm2/s or higher and 3.5 mm2/s or lower, a pour point of -25°C or lower, a viscosity index of 105 or greater, a %CP of 85 or greater, a %can of 2 or greater and 20 or less and a %CA of 3 or less in an amount of 50 to 97 percent by mass on the total base oil composition mass basis and (B) a monoester-based base oil having a 100°C kinematic viscosity of 2 to 10 mm2/s in an amount of 3 to 10 percent by mass on the total base oil composition mass basis; (C) a phosphorus acid ester in such an amount that the phosphorus content of the composition is from 250 to 350 ppm by mass on the phosphorus basis; and (D) a boronated ashless dispersant in an amount of 30 to 120 ppm by mass on the boron basis on the total lubricating oil composition mass basis, the ratio of the mass percent of boron to the mass percent of phosphorus in the composition (B/P) being from 0.07 to 0.42 and the composition having a 100°C kinematic viscosity of 2.5 to 4.0 mm2/s.
本发明涉及一种润滑油组合物,该组合物具有更好的节油性能,同时还具有优异的
金属抗疲劳性能和耐热性能,因此本发明提供了一种用于变速器的润滑油组合物,该组合物包括: 润滑基础油,该基础油包括 (A) 矿物基础油,该矿物基础油的 100°C 运动粘度为 1.5 mm2/s或更低、倾点为-25°C或更低、粘度指数为105或更高、%CP为85或更高、%can为2或更高和20或更低、%CA为3或更低的矿物基础油,其用量为基础油组合物总质量的50%至97%;(B) 100°C运动粘度为2至10 mm2/s的单酯型基础油,其用量为基础油组合物总质量的3%至10%;(D)
硼化无灰分散剂,其用量为润滑油组合物总质量的 30 至 120ppm(以
硼为基础),组合物中
硼的质量百分数与
磷的质量百分数之比 (B/P) 为 0.07 至 0.42,组合物中
硼的质量百分数与
磷的质量百分数之比 (B/P) 为 0.07 至 0.42,组合物的 100°C 运动粘度为 2.5 至 4.0 mm2/s。