use of a oelzusammensetzung to innenverbrennungsmotorkraftstoffsparungsverbesserung

摘要

An engine lubricating oil composition, free of organic ammonium thiophosphate, comprises an oil of lubricating viscosity and a fuel improving amount of:(A) a compound of formula where R1-R4 each = hydrocarbyl; X1 and X2 each = oxygen or sulphur; n = 0-3 and (B) an acylated nitrogen-containing compound containing 10+C aliphatic substituent. Also claimed is a method for improving fuel efficiency in an internal combustion engine involves operating the engine on the above composition.