A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil includes greater than 50 wt. % of a base oil, one or more overbased calcium-containing detergents, one or more overbased magnesium-containing detergents and one or more molybdenum compounds and leads to a more than 60% reduction in LSPI compared to the LSPI of a reference oil and passes the Ball Rust Test. The ratio of wt % calcium from the overbased detergents to wt. % of magnesium from the overbased detergents is less than 11.9. A ratio of total ppm of magnesium to total TBN of the lubricating oil in mg KOH/g is greater than 19. A ratio of the total ppm of calcium to the total TBN of the lubricating oil is less than 222. The oil and method may reduce low-speed pre-ignition events in a boosted internal combustion relative to commercially available lubricating oils.

Disclosed is a lubricating oil composition containing a base oil, a viscosity index improver, a molybdenum-based friction modifier, a boron-containing dispersant, and at least two extreme-pressure additives selected from a sulfur-based extreme-pressure additive, a phosphorous-based extreme-pressure additive and a sulfur/phosphorus-based extreme-pressure additive, or a sulfur/phosphorus-based extreme-pressure additive. The base oil is a synthetic oil having a kinematic viscosity at 100 C. of 3 mm.sup.2/s or more and 10 mm.sup.2/s or less, the viscosity index improver is a resin having a number average molecular weight (Mn) of 1,000 or more and 10,000 or less, the mass ratio of boron atoms (B) contained in the boron-containing dispersant to molybdenum atoms (Mo) contained in the molybdenum-based friction modifier, [(B)/(Mo)] is 1 or more and 5 or less, and the mass ratio of sulfur atoms (S) to phosphorus atoms (P) contained in the extreme-pressure additive(s), [(S)/(P)] is 10 or more and 20 or less.

The present invention relates to lubricant compositions for motorcycle engines where the crankcase lubricant is also used to lubricate a wet clutch. The lubricant compositions contain antimony dithiocarbamates in combination with one or more ash-free friction modifiers.

The invention relates to a method of lubricating an internal combustion engine comprising supplying to the engine a lubricating composition comprising: an oil of lubricating viscosity, 2.3 wt % to 4 wt % of a dispersant package, wherein the dispersant package comprises: a borated succinimide dispersant obtainable by an ene reaction of a polyalkylene with an acylating agent to form an intermediate, reacting the intermediate with an aminoalcohol or amine to form a dispersant, and reacting the dispersant with a borating agent to form a borated succinimide dispersant; and a non-borated succinimide dispersant obtained by a Diels-Alder reaction. The ratio of non-borated succinimide dispersant to borated succinimide dispersant is 90:10 to 20:80, and the borated succinimide has 0.2 wt % to 1.3 wt % boron on an oil-free basis of the dispersant.

The lubricating oil composition of the present invention is a lubricating oil composition containing a lubricating base oil, a metal-based detergent, a molybdenum dialkyldithiocarbamate compound, and a boron-containing compound, wherein the metal-based detergent contains a calcium salicylate and at least one selected from the group consisting of a calcium sulfonate and a magnesium-based detergent; the lubricating oil composition arbitrarily contains an ashless friction modifier; the content of a calcium atom is 0.12 to 0.16 mass % on the basis of the whole amount of the lubricating oil composition; the content of a molybdenum atom is 0.05 to 0.10 mass % on the basis of the whole amount of the lubricating oil composition; and a predetermined coefficient X is less than 0.050.

The present invention provides a lubricating oil composition including a viscosity index improver (A) containing a comb-shaped polymer and having an SSI (shear stability index) of 30 or less together with a base oil, wherein an HTHS viscosity (high temperature high shear viscosity) at 150 C. (T.sub.150) is 1.6 to 2.9 mPa.Math.s, and a ratio of a kinematic viscosity at 40 C. (V.sub.40) [mm.sup.2/s] to the HTHS viscosity at 150 C. (T.sub.150) [mPa.Math.s] (V.sub.40/T.sub.150) is 12.4 or less. The lubricating oil composition of the present invention is excellent in fuel consumption reducing properties in a low-temperature region assuming the time of starting an engine while making various properties, such as a viscosity, etc., in a high-temperature region assuming the time of high-speed operation of an engine favorable.

A lubricating oil composition which exhibits an excellent friction-reducing effect and excellent fuel consumption reducing properties is provided.

The lubricating oil composition includes a lubricating base oil (A), a molybdenum compound (B), and an ashless friction modifier (C), wherein the lubricating oil composition includes a binuclear organic molybdenum compound represented by the following general formula (I) as the molybdenum compound (B), with the content of the binuclear organic molybdenum compound as converted into molybdenum atoms being 0.030 mass % or more and 0.140 mass % or less based on the total amount of the lubricating oil composition; and an ester-based ashless friction modifier (C1) and/or an amine-based ashless friction modifier (C2) as the ashless friction modifier (C), with the total content of the ester-based ashless friction modifier (C1) and the amine-based ashless friction modifier (C2) being more than 0.1 mass % and 1.8 mass % or less based on the total amount of the lubricating oil composition:

##STR00001## in the general formula (I), R.sup.1 to R.sup.4 each represents a hydrocarbon group having 4 to 22 carbon atoms, R.sup.1 to R.sup.4 may be the same as or different from each other, and X.sup.1 to X.sup.4 each represents a sulfur atom or an oxygen atom.

A lubricant composition comprising (a) an oil of lubricating viscosity; (b) a (meth)-acrylate-containing polymer comprising a multiplicity of arms containing at least 20 carbon atoms, said arms being attached to a multivalent organic moiety; and (c) an ethylene/olefin copolymer having a weight average molecular weight of about 10,000 to about 250,000, wherein the copolymer comprises about 40 to about 70 weight percent polymerized ethylene monomers and optionally further comprises polymerized propylene monomers; exhibits good viscometric and antiwear properties.

The disclosed technology relates to compositions suitable for use as lubricants and lubricant additive compositions which comprise a 1,4-benzoxazine-derived antioxidant, wherein the antioxidant itself may also be described as a 1,4-benzoxazine compound, and optionally comprising other additives suitable for lubricants, such as an anti-wear agent, a detergent, or a dispersant.

This invention relates to a method of reducing abnormal combustion events in a hydrogen fueled internal combustion engine (HICE) during operation of the engine. The method includes the steps of: a) providing to the HICE a lubricating oil composition including or resulting from the admixing of: i) a base oil having a viscosity KV100 of less than or equal to 12 cSt and included at greater than 50 wt. % of the composition and comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof; ii) an overbased magnesium containing detergent comprising an overbased magnesium salicylate, an overbased magnesium sulfonate, an overbased magnesium phenate, or combinations thereof with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and included at treat level to deliver between 100 to 5000 ppm by weight of total magnesium; iii) an overbased metal-containing detergent comprising an overbased metal salicylate detergent, an overbased metal phenate detergent, or combinations thereof with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and included at treat level to deliver between 100 to 5000 ppm by weight of total metal; and wherein the overbased magnesium containing detergent of ii) and the overbased metal-containing detergent of iii) in combination deliver between 0.15 wt. % to 8.0 wt. % of total soap to the composition; iv) at least one zinc dihydrocarbyl dithiophosphate compound included at a treat level to deliver more than 100 ppm by weight of zinc and less than 800 ppm by weight of phosphorus to the composition; v) at least one molybdenum containing compound included at a treat level to deliver between 20 to 2000 ppm by weight of total molybdenum to the composition; vi) at least one silicon containing compound included at a treat level to deliver between 5 to 1000 ppm by weight of total silicon to the composition; and vii) the lubricating oil composition having a total sulfated ash of less than or equal to 2.0 wt. %, a total phosphorous level of less than or equal to 800 ppm by weight and a SAE viscosity grade of 25W-X, 20W-X, 15W-X, 10W-X, 5W-X or 0W-X, where X represents any one of 8, 12, 16, 20, 30, 40, 50 or 60; b) providing a fuel comprising hydrogen to the HICE; and c) combusting the fuel in the HICE. Also provided are a lubricating oil composition and a concentrate for use in a HICE to reduce the propensity for abnormal combustion events.