Abstract: Disclosed is a method for operating an internal combustion engine, wherein fuel is injected in a pre-injection and main injection process. According to the invention, pre-injection occurs in the intermediate compression stroke of the internal combustion engine. Main injection is carried out in an intake synchronous manner. The invention can be used for internal combustion engines, particularly for passenger cars and commercial vehicles.

Abstract: In a method of operating an internal combustion engine in which exhaust gas is retained in the combustion chamber of the internal combustion engine and compressed during a charge change together with fresh combustion air, a first fuel quantity is injected into the retained exhaust gas by means of direct fuel injection, a second fuel quantity is subsequently supplied to the combustion chamber together with the fresh combustion air so that a homogeneous fuel/gas/air mixture is formed in the combustion chamber, and an auto-ignition time of the fuel/gas/air mixture is established as a function of a quantity ratio of the first fuel quantity and the second fuel quantity.

Abstract: A method includes the steps of delivering a main combustion air quantity and a main fuel quantity, from which a main mixture is formed, to the combustion chamber; igniting the main mixture formed in an area of a ignition top dead center; and introducing an additional combustion air quantity and an additional fuel quantity into the combustion chamber after the combustion of the main mixture in such a way that a fuel-exhaust gas/air mixture is formed, which mixture is reacted in an area of a gas exchange top dead center of the piston.

Abstract: In a method for operating an internal combustion engine with direct fuel injection, in which air and a first fuel quantity are fed to a combustion chamber, in such a manner that a homogenous lean base mixture is formed in the combustion chamber, and a second fuel quantity is introduced into the combustion chamber in the region of a top dead center position of the piston, in such a manner that an ignitable mixture cloud is formed within the homogenous lean base mixture in the region of an ignition source, and the mixture cloud formed by the second fuel quantity is ignited by means of the ignition source, so that the lean homogenous base mixture which is present in the combustion chamber is compressed by the combustion of the mixture cloud formed by the second fuel quantity and ignited thereby.

Abstract: An engine exhaust silencer arrangement with a variable geometry, which is controlled by control elements in dependence of engine data. The increased exhaust noise occurring during engine operation under differing engine stroke modes is suppressed by the different geometry of the silencer arrangement.