Each of a lubricant oil additive and a lubricant oil composition according to the present invention contains the viscosity index improver.

Also disclosed is a lubricating oil composition containing such a lubricating oil additive.

Each lubricant oil additive, generally patented, has its own manufacturing process.

Disclosed is a lubricating oil additive with excellent cleaning performance which does not include a metal component such as calcium or magnesium.

Also disclosed is a lubricating oil composition containing a mineral oil and/or a synthetic base oil and the lubricating oil additive.

Disclosed is a lubricating oil additive which is composed of a reaction product of a succinimide compound and a fluorine atom-containing compound.

An improved overbased sulfurized alkaline earth metal phenate detergent lubricating oil additive and the process for its preparation are disclosed.

The lubricating oil additive is able to adjust frictional properties to a suitable level.

A further aspect is directed to a lubricating oil composition and a lubricating oil additive concentrate having the aminomethyl-substituted imidazole compounds of the present invention.

A lubricating oil additive composition characterized in containing a boronated succinimide derivative, and an amino alcohol compound.

The lubricating oil additive is characterized by containing a quaternary ammonium salt having a base number of at least 10 mgKOH/g.