Disclosed is an internal combustion engine lubricating oil composition for reducing corrosion in the engine of a hybrid vehicle. Reduction of corrosion can be determined by the JIS K2246 test method. Also disclosed are methods for using said lubricating oil composition for reducing corrosion in the engine of a hybrid vehicle.

A method for utilizing a lubricating oil composition in which the content of a metal-based cleaning agent (X) having a base value of 100 mgKOH/g or less is 630 mass ppm or less in terms of metal atoms, and the content of sulfated ash is 1.5 mass % or less. The method includes measuring at least one physical property value among the capacitance and the dielectric constant of the lubricating oil composition while using the lubricating oil composition, and evaluating the progress of degradation of the lubricating oil composition.

A method for utilizing a lubricating oil composition in which the content of a metal-based cleaning agent (X) having a base value of 100 mgKOH/g or less is 630 mass ppm or less in terms of metal atoms, and the content of sulfated ash is 1.5 mass % or less. The method includes measuring at least one physical property value among the capacitance and the dielectric constant of the lubricating oil composition while using the lubricating oil composition, and evaluating the progress of degradation of the lubricating oil composition.

A lubricating oil composition including a major amount of a base oil, one or more calcium-containing detergents to provide at least 1000 ppmw of calcium, and one or more silicon-containing compound(s) to provide at least 50 ppmw of silicon to the lubricating oil composition, all based on the total weight of the lubricating oil composition, wherein a ratio of ppmw of silicon provided by the one or more silicon-containing compound(s) to the lubricating oil composition to the ppmw of calcium provided by the one or more calcium-containing detergent(s) to the lubricating oil composition is from 0.02 to 1. Methods of using these compositions and silicon-containing detergents are also described.

The present invention provides a lubricant composition comprising a base oil of lubricating viscosity, wherein the base oil comprises an ether base stock of formula (A), where: R.sub.a and R.sub.b are aliphatic hydrocarbyl groups and may be the same or different; the lubricant composition further comprising at least one aminic anti-oxidant and at least one phenolic anti-oxidant. In some embodiments, the ether base stock has the formula (1), where: R.sub.1 R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are as defined herein. The lubricant composition may be used for lubricating a surface in an internal combustion engine as well as for improving the fuel economy performance and/or piston cleanliness performance of an engine and/or a vehicle, such as an automotive vehicle associated with an internal combustion engine. ##STR00001##

A lubricating oil composition is provided which comprises (a) greater than 50 wt. % of a base oil of lubricating viscosity; and (b) 0.1 to 40 wt. % of an overbased alkaline earth metal alkyl-substituted hydroxyaromatic carboxylate having a TBN, on an actives basis, of at least 600 mg KOH/g, as determined by ASTM D 2896; wherein the lubricating oil composition is a monograde lubricating oil composition meeting specifications for SAE J300 revised January 2015 requirements for a SAE 20, 30, 40, 50, or 60 monograde engine oil, and has a TBN of 5 to 200 mg KOH/g, as determined by ASTM D2896.

Alkyl salicylic acids, overbased detergents derived from alkyl salicylic acids, lubricating compositions including the alkyl salicylic acids and/or overbased detergents, and processes of making and using the same, are described.

Alkyl salicylic acids, overbased detergents derived from alkyl salicylic acids, lubricating compositions including the alkyl salicylic acids and/or overbased detergents, and processes of making and using the same, are described.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an ashless dispersant. The ashless dispersant may be selected from succinimide compounds prepared from aliphatic or aromatic amines.

Lubricating oil composition is provided. The composition includes several components including a base oil, a primary antioxidant including alkylated diphenylamines having an alkyl group derived from a propylene tetramer; and a sulfonate detergent.