Lubricating oil composition
AssigneeInfineum International Limited
InventorsAlastair A. Cant, Adam P. Marsh, Robert W. Shaw, Thomas D. Wilkinson
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Abstract
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.
Claims23
A method for reducing low-speed pre-ignition events and/or improving oxidation performance in a spark-ignited direct injection internal combustion engine, the method comprising lubricating the crankcase of the engine, that in operation is susceptible to the occurrence of low-speed pre-ignition events, with a lubricating oil composition which comprises a detergent additive comprising an oil-soluble basic organic acid salt including at least magnesium and calcium as cations, wherein the weight ratio of calcium to magnesium is 1:1 to 1:3, and the organic acid is an alkyl-substituted hydroxy-benzoic acid or a sulfonic acid, and operating the engine.
A method for reducing low-speed pre-ignition events and/or improving oxidation performance in a spark-ignited direct injection internal combustion engine, the method comprising lubricating the crankcase of the engine, that in operation is susceptible to the occurrence of low-speed pre-ignition events, with a lubricating oil composition which comprises an oil-soluble calcium and magnesium sulfonate or an oil-soluble calcium and magnesium salicylate, where the weight ratio of calcium to magnesium is 1:1 to 1:3, as a detergent additive, and operating the engine.
Dependencies are inferred from the claim text.