US Patent 9243579 Method for operating an auto-ignition internal combustion engine

A method for operating an auto-ignition internal combustion engine that is operable in a single substance mode in which the internal combustion engine is supplied with self-igniting liquid fuel, and a dual substance mode in which the internal combustion engine is supplied with the liquid fuel as an ignition agent and gaseous or liquid alternative fuel, includes operating the internal combustion engine in the dual-substance mode at an increased exhaust gas recirculation rate relative to the single-substance mode, and throttling an air supply in an intake system of the internal combustion engine such that a lambda value in an exhaust gas of the internal combustion engine is in a range greater than 1 up to 1.3.