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 (1.0Ca.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.

Disclosed herein is an oil additive and combination oil product comprising an effective amount of the oil additive. The oil additive comprises a bismuth-containing premix, the bismuth-containing premix comprising bismuth trioxide and a carrier, and a boron-containing premix, the boron-containing premix comprising boric acid, a carrier, and an anionic surfactant.

Disclosed herein is an oil additive and combination oil product comprising an effective amount of the oil additive. The oil additive comprises a bismuth-containing premix, the bismuth-containing premix comprising bismuth trioxide and a carrier, and a boron-containing premix, the boron-containing premix comprising boric acid, a carrier, and an anionic surfactant.

It is an object of this invention to provide a lubricant additive applicable integrally to all of different types of lubricants for various applications. A lubricant additive adapted to be blended to a lubricating oil, which is characterized by comprising a synthesized base oil of the polyolester type, the content of which to be contained in the lubricant additive is in a range of from 30.0 w/w % to 60.0 w/w %, calcium sulfonate containing calcium carbonate formed in the calcite crystal structure, the content of which to be contained in the lubricant additive is in a range of from 5.0 w/w % to 30.0 w/w %, a poly-alpha-olefin oligomer, an anti-oxidant of the zinc dithiophosphate type, succinimide, an extreme pressure agent of the thiadiazole type and an anti-oxidant of the phenol type, is provided.

A method for preventing or reducing low speed pre-ignition in an engine lubricated with a lubricating oil while maintaining or improving cleanliness by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and at least one boron-containing compound and at least one overbased calcium detergent as minor components. The at least one boron-containing compound includes at least one borated dispersant, or a mixture of a boron-containing compound and a non-borated dispersant. The boron to nitrogen ratio for the at least one boron-containing compound is less than or equal to about 0.3 and the lubricating oil is essentially free of elemental magnesium. The lubricating oils of this disclosure are particularly advantageous as passenger vehicle engine oil (PVEO) products.

A method for preventing or reducing low speed pre-ignition in an engine lubricated with a lubricating oil while maintaining or improving cleanliness by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and at least one boron-containing compound and at least one overbased calcium detergent as minor components. The at least one boron-containing compound includes at least one borated dispersant, or a mixture of a boron-containing compound and a non-borated dispersant. The boron to nitrogen ratio for the at least one boron-containing compound is less than or equal to about 0.3 and the lubricating oil is essentially free of elemental magnesium. The lubricating oils of this disclosure are particularly advantageous as passenger vehicle engine oil (PVEO) products.

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.

There is provided a lubricating oil composition which is excellent in the wear resistance and the oil film retention even when the viscosity of the composition is lowered. The lubricating oil composition comprises: a base oil (A); an imide compound (B); a calcium-based detergent (C); a polymer component (D); and a zinc dithiophosphate (E), wherein the imide compound (B) comprises at least one non-boron-modified succinic acid imide compound (Bx) selected from a succinic acid monoimide (B1x) represented by general formula (b-1) and a succinic acid bisimide (B2x) represented by general formula (b-2), and wherein the polymer compound (D) has a mass average molecular weight (Mw) of not less than 10,000 and not more than 50,000, and comprises at least one selected from an olefin polymer (D1) and a polymethacrylate (D2).

There is provided a lubricating oil composition which is excellent in the wear resistance and the oil film retention even when the viscosity of the composition is lowered. The lubricating oil composition comprises: a base oil (A); an imide compound (B); a calcium-based detergent (C); a polymer component (D); and a zinc dithiophosphate (E), wherein the imide compound (B) comprises at least one non-boron-modified succinic acid imide compound (Bx) selected from a succinic acid monoimide (B1x) represented by general formula (b-1) and a succinic acid bisimide (B2x) represented by general formula (b-2), and wherein the polymer compound (D) has a mass average molecular weight (Mw) of not less than 10,000 and not more than 50,000, and comprises at least one selected from an olefin polymer (D1) and a polymethacrylate (D2).

The present disclosure relates to passenger car motor oil lubricating oil compositions having select dispersant and detergent systems to improve at least one of deposits, sludge, oxidization, and wear when using a blend of API Group II base oils with one or more API Group III and/or API Group IV base oils. The dispersant systems herein includes select amounts of boron, nitrogen, and total base number contributions that surprisingly achieve performance even when including higher amounts of the API Group II base oils in the lubricants.