Patent ID: 9637703
Date: 2017-05-02
CPC Classifications: C10M,C10N

Claim:
1. A lubricating oil composition comprising: a lubricating base oil with a 100° C. kinematic viscosity of 1-20 mm molybdenum dithiocarbamate (MoDTC) in an amount of 0.03-0.1% by mass in terms of molybdenum element and based on the total mass of the lubricating oil composition, a first overbased metal salt obtained by overbasing an oil-soluble metal salt with an alkaline earth metal borate in an amount of 0.05-5% by mass based on the total mass of the lubricating oil composition, a second overbased metal salt obtained by overbasing an oil-soluble metal salt with an alkaline earth metal carbonate in an amount of 0.05-2.2% by mass based on the total mass of the lubricating oil composition, and 3-20% by mass based on the total mass of the lubricating composition of a poly(meth)acrylate-based viscosity index improver with a PSSI of no greater than 35 and a ratio between the molecular weight and PSSI (Mw/PSSI) of 1×10 wherein the total of the metal content from the first overbased metal salt and from the second overbased metal salt in the lubricating oil composition is 0.1 to 0.3% by mass.