Lubricating oil composition for engine equipped with supercharging mechanism, method for suppressing low-speed pre-ignition in engine equipped with supercharging mechanism using lubricating oil composition, and method for manufacturing lubricating oil composition

Abstract

Provided is a lubricating oil composition for engine equipped with a forced-induction mechanism capable of lowering the frequency of occurrence of LSPI, while using a calcium-based detergent. The lubricating oil composition for engine equipped with a forced-induction mechanism contains a base oil (A), a metal-containing surfactant (B) containing at least a calcium-containing surfactant (b1), and at least one basic compound (C) selected from a metal carbonate, a metal hydroxide, and an amine-based compound, wherein the content of sulfur contained in the metal-containing surfactant (B) is 0.2 mass % or more on the basis of the whole amount of the metal-containing surfactant (B); the content of a calcium atom is 0.08 to 0.20 mass % on the basis of the whole amount of the composition; and a mass ratio of the content of the basic compound (C) and the content of a calcium atom derived from the calcium-containing surfactant (b1) [(content of (C))/(calcium content derived from (b1))] is 2.0 or more.

Dependencies are inferred from the claim text.