COMPOSITION AND METHOD FOR PREVENTING OR REDUCING ENGINE KNOCK AND PRE-IGNITION IN HIGH COMPRESSION SPARK IGNITION ENGINES

摘要

A method for preventing or reducing engine knock or pre-ignition in a high compression spark ignition engine lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition that contains (i) a lubricating oil base stock comprising at least one branched ester having at least about 15% of the total carbons in the form of methyl groups, and (ii) at least one ashless antiwear additive selected from a phosphorus-containing ashless antiwear additive, a sulfur-containing ashless antiwear additive, and a phosphorus/sulfur-containing ashless antiwear additive. A lubricating engine oil having a composition that contains (i) a lubricating oil base stock comprising at least one branched ester having at least about 15% of the total carbons in the form of methyl groups, and (ii) at least one ashless antiwear additive selected from a phosphorus-containing ashless antiwear additive, a sulfur-containing ashless antiwear additive, and a phosphorus/sulfur-containing ashless antiwear additive. The lubricating oils of this disclosure are useful as passenger vehicle engine oil (PVEO) products.

主权项

1. A method for preventing or reducing engine knock or pre-ignition in a high compression spark ignition engine lubricated with a lubricating oil by using as the lubricating oil a formulated oil, said formulated oil having a composition comprising (i) a lubricating oil base stock comprising at least one branched ester having at least 15% of the total carbons in the form of methyl groups, and (ii) at least one ashless antiwear additive selected from the group consisting of a phosphorus-containing ashless antiwear additive, a sulfur-containing ashless antiwear additive, and a phosphorus/sulfur-containing ashless antiwear additive.