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.

The present disclosure describes lubricant compositions effective to minimize average engine sludge through selection of lubricant additives that control the total nitrogen as well as the origin of the nitrogen in the lubricant composition. In aspects, the lubricant compositions herein include at least a base oil of lubricating viscosity, a dispersant system, and at least one antioxidant.

A lubricating oil composition having a fluorescent compound that emits a fluorescent light. The fluorescent compound has a property of deteriorating with relevance to a deterioration of the lubricating oil composition. A deterioration measurement device having a light emitter that emits an irradiation light toward a measurement target object including a fluorescent compound, a light receiver, and a sensor. A deterioration measurement system having a lubricating oil composition and a deterioration measurement device.

A lubricating oil composition may include a base oil (A), succinimide (B) which has not been modified with boron, succinimide (C) modified with boron, a metallic detergent (D), and an antioxidant (E), wherein the ratio of the content of boron atoms derived from ingredient (C) to the content of nitrogen atoms derived from ingredients (B) and (C), B/N, is 0.30 or less by mass, the lubricating oil composition satisfying requirement (I) and/or requirement (II). Requirement (I): Ingredient (D) includes a metallic detergent (D1) having a base value less than 100 mgKOH/g. Requirement (II): Ingredient (E) includes an amine-based antioxidant (E1), the content of ingredient (E1) being 1.00 mass % or less.

Provided is a lubricating oil composition to be used in an internal combustion engine having a sliding mechanism including a piston ring and a liner, the lubricating oil composition including: a base oil; (A) a poly(meth)acrylate; and (B) an organic molybdenum compound, in which: (A) the poly(meth)acrylate contains a polymer (A1) including a repeating unit derived from a (meth)acrylate represented by the following formula (1) and having a mass-average molecular weight of from 1,000 to 500,000; and a content of (B) the organic molybdenum compound in a total amount of the composition is from 0.01 mass % to 0.2 mass % in terms of a molybdenum atom: wherein R.sup.1 represents a hydrogen atom or a methyl group, and X represents a hydrogen atom, a hydrocarbon group having 1 to 60 carbon atoms, or a functional group-containing hydrocarbon group having 1 to 60 carbon atoms.

The lubricating oil composition according to the present invention is one including a base oil, (A) a substituted hydroxy aromatic carboxylic acid ester derivative represented by at least one of the general formula (I) and the general formula (II), and (B) a heterocyclic compound represented by the general formula (III) or (IV) blended therein, wherein a phosphorus content is 0.06 mass % or less on the basis of a total amount of the composition, and a sulfated ash content is 1.2 mass % or less on the basis of a total amount of the composition. The lubricating oil composition is capable of maintaining high-temperature detergency and acid neutralizing properties, even when amounts of a phosphorus component-containing additive and a metallic detergent are reduced.

Lubricating composition comprising (i) base oil and (ii) a Verkade base compound having the formula (1): wherein R.sup.1, R.sup.2 and R.sup.3 are each independently selected from hydrogen and saturated or unsaturated, straight chain or branched, C.sub.1-C.sub.22 alkyl groups. The lubricating composition of the present invention exhibits improved base number retention and oxidative stability, particularly in the presence of a biofuel such as fatty acid alkyl ester.

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The disclosed technology provides a lubricating composition comprising an oil of lubricating viscosity and 0.01 wt % to 10 wt % of an oxyalkylated aromatic polyol compound, wherein the aromatic compound has at least one alkoxy group represented by −OR.sup.1 group, R.sup.1 is hydroxyalkyl, or a (poly)ether group, and either: at least one hydroxyl group, or at least one alkoxy group represented by —OR.sup.1 group, where R.sup.1 is alkyl, or a (poly)ether group, or at least one oxyalkyl group represented by —OR.sup.1, where R.sup.1 is hydroxyalkyl or a (poly)ether group. The disclosed technology further relates to a method of lubricating a mechanical device (such as an internal combustion engine) with the lubricating composition. The disclosed technology further relates to the use of the oxyalkylated aromatic polyol compound in the lubricating composition to a passenger car internal combustion engine at least one of (i) control of fuel economy, (ii) control of corrosion, (iii) cleanliness, and (iv) control of bore wear.

The present disclosure relates to a lubricating fluid for an electric motor system and a method of lubricating gears and cooling a motor in an electric motor system. In particular, the disclosed technology relates to a lubricating fluid, for use in electric motor vehicle, comprising an oil of lubricating viscosity and at least one phosphorylated dispersant exhibiting increased resistivity after aging.

A lubricating oil composition comprising greater than 50 wt.% of a base oil of lubricating viscosity, and either: a) an additive composition comprising: one or more zinc, dialkyl dithiophosphates (ZDDP compounds) and one or more dispersants, wherein the amount of zinc (Zn) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds multiplied by the contribution of the total base number (TEN) of the one or more dispersants to the TEN of the lubricating oil composition is a multiplication factor Zn*TBNDisp of at least about 0.06; or b) an additive composition comprising: one or more zinc dialkyl dithiophosphates (ZDDP compounds) and one or more dispersants, wherein the amount of phosphorus (P) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds multiplied by the contribution of the total base number (TBN) of the one or more dispersants to the TBN of the lubricating oil composition is a multiplication factor P*TBNDisp of at least about 0.051.