A lubricating oil composition for reducing low-speed pre-ignition events or improving oxidation in a spark-ignited direct injection engine is disclosed. The composition includes a detergent additive which comprises either: an oil-soluble sulfonate including both magnesium and calcium as cations; or an oil-soluble salicylate including both magnesium and calcium as cations.

A lubricating oil composition for reducing low-speed pre-ignition events or improving oxidation in a spark-ignited direct injection engine is disclosed. The composition includes a detergent additive which comprises either: an oil-soluble sulfonate including both magnesium and calcium as cations; or an oil-soluble salicylate including both magnesium and calcium as cations.

A sulfonate-based grease composition and method of manufacture comprising (1) addition of both overbased calcium sulfonate and overbased magnesium sulfonate in a ratio range of 60:40 to 100:1, with the magnesium sulfonate added all at once, a portion prior to conversion and another portion after conversion, and/or one more delay periods between the addition of water or other reactive ingredient and the addition of magnesium sulfonate; (2) one or more delay periods between the addition of at least a portion of a facilitating acid and at least a portion of the next subsequently added ingredient; (3) no conventional non-aqueous converting agents added prior to conversion; or (4) a combination thereof. The grease has a high dropping point and reduced thickener yield.

A sulfonate-based grease composition and method of manufacture comprising (1) addition of both overbased calcium sulfonate and overbased magnesium sulfonate in a ratio range of 60:40 to 100:1, with the magnesium sulfonate added all at once, a portion prior to conversion and another portion after conversion, and/or one more delay periods between the addition of water or other reactive ingredient and the addition of magnesium sulfonate; (2) one or more delay periods between the addition of at least a portion of a facilitating acid and at least a portion of the next subsequently added ingredient; (3) no conventional non-aqueous converting agents added prior to conversion; or (4) a combination thereof. The grease has a high dropping point and reduced thickener yield.

A lubricating oil composition including: a lubricant base oil; (A) a calcium salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of calcium on the basis of the total mass of the composition; (B) a succinimide ashless dispersant in an amount of 0.005 to 0.25 mass % in terms of nitrogen on the basis of the total mass of the composition; (C) a nitrogen-containing antioxidant in an amount of 0.005 to 0.15 mass % in terms of nitrogen on the basis of the total mass of the composition; and optionally (D) a nitrogen-containing friction modifier in an amount of no more than 0.03 mass % in terms of nitrogen on the basis of the total mass of the composition, wherein a total content of any metallic detergent is 0.005 to 0.03 mass % in terms of metal on the basis of the total mass of the composition.

A lubricating oil composition including: a lubricant base oil; (A) a calcium salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of calcium on the basis of the total mass of the composition; (B) a succinimide ashless dispersant in an amount of 0.005 to 0.25 mass % in terms of nitrogen on the basis of the total mass of the composition; (C) a nitrogen-containing antioxidant in an amount of 0.005 to 0.15 mass % in terms of nitrogen on the basis of the total mass of the composition; and optionally (D) a nitrogen-containing friction modifier in an amount of no more than 0.03 mass % in terms of nitrogen on the basis of the total mass of the composition, wherein a total content of any metallic detergent is 0.005 to 0.03 mass % in terms of metal on the basis of the total mass of the composition.

A method for lubricating an internal combustion engine, the method including: supplying a lubricating oil composition to a cylinder of an internal combustion engine, wherein the internal combustion engine has a mean effective pressure of no less than 1.3 MPa, wherein an integrated intensity ratio of peaks of CaO in a X-ray diffraction spectrum of an ash is no more than 16.5%, the ash being obtained by incinerating the lubricating oil composition in an air at 950° C.

A method for lubricating an internal combustion engine, the method including: supplying a lubricating oil composition to a cylinder of an internal combustion engine, wherein the internal combustion engine has a mean effective pressure of no less than 1.3 MPa, wherein an integrated intensity ratio of peaks of CaO in a X-ray diffraction spectrum of an ash is no more than 16.5%, the ash being obtained by incinerating the lubricating oil composition in an air at 950° C.

The present invention provides a lubricating oil composition for two-wheeled vehicles, which is able to not only suppress a lowering of fatigue life of engine parts while making fuel saving properties (in particular, fuel saving properties at the time of low speed) favorable but also make clutch friction characteristics of two-wheeled vehicles favorable. The present invention is concerned with a lubricating oil composition for two-wheeled vehicles, including a base oil (A) having a viscosity index of 120 or more, an ethylene-propylene copolymer (B), and a metal-based detergent (C), wherein the content of the ethylene-propylene copolymer (B) is 0.30% by mass or more on the basis of the whole amount of the lubricating oil composition; the metal-based detergent (C) contains a calcium phenate (C1) and a calcium sulfonate (C2), and a mass ratio of the content (Ca.sub.1) of the calcium phenate (C1) as expressed in terms of a calcium atom to the content (Ca.sub.2) of the calcium sulfonate (C2) as expressed in terms of a calcium atom is satisfied with a relation of (1.0≤Ca.sub.1/Ca.sub.2); and the lubricating oil composition has a kinematic viscosity at 100° C. is less than 9.3 mm.sup.2/s and an HTHS viscosity at 150° C. is 2.9 mPa.Math.s or more.

The present invention provides a lubricating oil composition for two-wheeled vehicles, which is able to not only suppress a lowering of fatigue life of engine parts while making fuel saving properties (in particular, fuel saving properties at the time of low speed) favorable but also make clutch friction characteristics of two-wheeled vehicles favorable. The present invention is concerned with a lubricating oil composition for two-wheeled vehicles, including a base oil (A) having a viscosity index of 120 or more, an ethylene-propylene copolymer (B), and a metal-based detergent (C), wherein the content of the ethylene-propylene copolymer (B) is 0.30% by mass or more on the basis of the whole amount of the lubricating oil composition; the metal-based detergent (C) contains a calcium phenate (C1) and a calcium sulfonate (C2), and a mass ratio of the content (Ca.sub.1) of the calcium phenate (C1) as expressed in terms of a calcium atom to the content (Ca.sub.2) of the calcium sulfonate (C2) as expressed in terms of a calcium atom is satisfied with a relation of (1.0≤Ca.sub.1/Ca.sub.2); and the lubricating oil composition has a kinematic viscosity at 100° C. is less than 9.3 mm.sup.2/s and an HTHS viscosity at 150° C. is 2.9 mPa.Math.s or more.