| abstract |
An object of the present invention is to provide a lubricating oil composition exhibiting excellent wear resistance performance using a reduced level of ZDDP in a diesel engine. A lubricating oil composition, more specifically, a sulfated ash content of 1.0 mass% or less, a sulfur content of 0.4 mass% or less, a phosphorus content of 0.12 mass% or less, and a TBN of about 7 to A heavy-duty diesel (HDD) engine lubricating oil composition is provided, the lubricating oil composition comprising a majority amount of oil of lubricating viscosity, a sulfur-free phenolic antioxidant, an amine-based antioxidant, and At least 0.5% by weight of an ashless antioxidant selected from the group consisting of these mixtures and a small amount of overbased magnesium detergent, and at least the TBN provided to the lubricating oil composition by the overbased metal detergent. About 60% is provided by the overbased magnesium detergent. [Selection figure] None |