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 a boron-containing ashless dispersant. The ashless dispersant may be selected from succinimide compounds prepared from aliphatic or aromatic amines.

The lubricating oil composition for four-stroke cycle engine of the present invention includes a base oil (A) and from 0.5 to 10% by mass of a polyolefin (B) having at least an isobutene-derived constituting unit and having a number average molecular weight of 500 to 10,000, with a sulfated ash content being from 0.3 to 1.2% by mass.

Provided are lubricating engine oils including a lubricating oil base stock as a major component having a base oil viscosity at 100 deg. C. ranging from 4.5 to 7.5 cSt, and a carboxylic functionalized polymer dispersant with aromatic amine functionality, as a minor component, wherein the lubricating engine oils have a cold crank simulator viscosity at 30 deg. C. of less than 8500 mPa.Math.s. The lubricating engine oils may provide improved engine wear protection at equivalent fuel efficiency or improved fuel efficiency at equivalent engine wear protection compared to a lubricating engine oil containing a dispersant as a minor component other than the carboxylic functionalized polymer with aromatic amine functionality. Methods of making the lubricating engine oil are also provided. The lubricating engine oils are useful in internal combustion engines including direct injection, gasoline and diesel engines.

The present disclosure relates to novel organic friction modifiers for use in non-aqueous lubricant compositions, the organic friction modifiers comprising a product formed from the reaction of polyisobutylene succinic anhydride and a hydrophilic polyetheramine.

The present disclosure is directed to an additive composition for engine oils comprising; (a) an alkenyl-substituted succinic anhydride and (b) a polyamine compound and (C) Co-additives, wherein the reaction product has a ratio of the amide to imide infrared absorption peak areas of about 1:1.2 to about 1.6. The said reaction product is effective to prevent engine deposits along with protecting elastomeric seal material of an internal combustion engine and also improves piston cleanliness and ring sticking performance of an internal combustion engine.

The disclosed technology relates to a dispersant composition comprising the reaction product of a polyolefin acylating agent and an amine terminated or hydroxyl terminated polyether. In addition, the technology relates to lubricating compositions containing the dispersant composition and an optional synergistic amount of another dispersant, as well as methods of employing the dispersant composition in an engine and engine oils.

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 present invention aims to provide a viscosity index improver excellent in shear stability and having a low HTHS viscosity and a high viscosity index. The viscosity index improver of the present invention contains a (co)polymer (A) containing a polyolefin-based monomer as an essential monomer unit, and a base oil, wherein the absolute value of difference in solubility parameter between the (co)polymer (A) and the base oil is 0.8 to 2.0 (cal/cm.sup.3).sup.1/2.

The invention provides a dispersant viscosity modifier, and more specifically a metal free dispersant viscosity modifier. The invention provides compositions, including lubricating compositions containing the described dispersant viscosity modifier, such as heavy duty diesel lubricating compositions. The invention further relates to the use of the described dispersant viscosity modifier to improve the film thickness and/or antiwear performance of a lubricating composition, for example, a heavy duty diesel lubricating composition. The improved dispersant viscosity modifier of the invention is specially designed to protect against valve train and other crankcase wear in lubricating applications, including heavy soot conditions such as heavy duty diesel lubricating applications.

The present invention relates to novel acid-free quaternized nitrogen compounds, to the preparation thereof and to the use thereof as a fuel and lubricant additive, more particularly as a detergent additive, as a wax antisettling additive (WASA) or as an additive for reducing internal diesel injector deposits (IDID); to additive packages which comprise these compounds; and to fuels and lubricants thus additized. The present invention further relates to the use of these acid-free quaternized nitrogen compounds as a fuel additive for reducing or preventing deposits in the injection systems of direct-injection diesel engines, especially in common-rail injection systems, for reducing the fuel consumption of direct-injection diesel engines, especially of diesel engines with common-rail injection systems, and for minimizing power loss in direct-injection diesel engines, especially in diesel engines with common-rail injection systems.