Disclosed is a lubricating engine oil composition for a direct injected, boosted, spark ignited internal combustion engine comprising from about 25 to about 3000 ppm of metal from at least one manganese-containing compound, based on the total weight of the lubricating oil. Also disclosed is a method for preventing or reducing low speed pre-ignition in an engine lubricated with said lubricating engine oil composition.

A lubricant composition for high compression spark ignition engines that contains at least one bismuth-containing compound (e.g., a bismuth salt of a carboxylic acid). A method for preventing or reducing engine knock and pre-ignition in an engine lubricated with a formulated oil. The formulated oil has a composition including at least one bismuth-containing compound (e.g., a bismuth salt of a carboxylic acid). A fuel composition for high compression spark ignition engines that contains at least one bismuth-containing compound (e.g., a bismuth salt of a carboxylic acid). A method for preventing or reducing engine knock and pre-ignition in an engine by using a fuel additive composition in a gasoline fuel composition. The fuel additive composition contains at least one bismuth-containing compound (e.g., a bismuth salt of a carboxylic acid). The lubricating oils of this disclosure are useful 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.

This invention relates to a lubricating oil composition comprising: at least 50 mass % or more of one or more base oils; detergent; and 0.01 to 20 mass % of a functionalized polymer comprising a partially or fully saturated olefin homopolymer or copolymer backbone and at least one functional group, having: i) an Mn of 10,000 g/mol or more (GPC-PS) of the polymer prior to functionalization, ii) where in the functional group is derived from an acylating agent and a compound containing amino and/or hydroxyl groups, and iii) optionally, wherein the homopolymer or copolymer backbone is derived from monomers selected from the group consisting of C.sub.2 to C.sub.30 (such as linear) alpha olefins and C.sub.4 to C.sub.20 conjugated dienes; where PIBSA-PAM having an Mn of 1,600 g/mol or more (GPC-PS) is absent or substantially absent from the lubricating oil composition, or, if present, is present in an amount such that the weight ratio of the functionalized polymer (B) to the high molecular weight PIBSA-PAM is at least 0.25:1.