Abstract: A method for setting an exhaust gas recirculation rate in an engine system having an internal combustion engine, the exhaust gas recirculation rate indicating the portion of the exhaust gas recirculated into one cylinder of the internal combustion engine with regard to the total gas quantity present in the cylinder, including: operating the internal combustion engine according to an input for the exhaust gas recirculation rate, an ignition of an air/fuel mixture being carried out in the cylinder at a certain ignition timing; adjusting the ignition timing in the cylinder of the internal combustion engine; correcting the input for the exhaust gas recirculation rate as a function of a change in an operating behavior of the internal combustion engine due to the ignition timing adjustment.

Abstract: A method for determining the composition of a fuel mixture consisting of a first fuel and a second fuel to operate an internal combustion engine having at least one cylinder pressure sensor for determining the cylinder pressure in at least one cylinder of the internal combustion engine. The calorific value of the fuel mixture or a characteristic variable correlating to said calorific value is determined from the cylinder pressure and the composition of the fuel mixture is determined from said calorific value or the characteristic variable correlating to said calorific value.

Abstract: A method for setting an exhaust gas recirculation rate in an engine system having an internal combustion engine, the exhaust gas recirculation rate indicating the portion of the exhaust gas recirculated into one cylinder of the internal combustion engine with regard to the total gas quantity present in the cylinder, including: operating the internal combustion engine according to an input for the exhaust gas recirculation rate, an ignition of an air/fuel mixture being carried out in the cylinder at a certain ignition timing; adjusting the ignition timing in the cylinder of the internal combustion engine; correcting the input for the exhaust gas recirculation rate as a function of a change in an operating behavior of the internal combustion engine due to the ignition timing adjustment.

Abstract: A method for influencing the exhaust gas temperature of an internal combustion engine is described in which measures can be carried out for increasing, lowering and limiting exhaust gas temperature. Depending on temperature requirements, and in which method these temperature requirements are prioritized, the temperature limitation having the highest priority for ensuring protection of the component parts, the resulting temperature requirement may be achieved by heating measures or cooling measures in such a way that heating measures and cooling measures are not applied at the same time.

Abstract: A method is provided for operating a spark ignition internal combustion engine having fuel injection at a cold start. The method retards the spark angle to a cold start value at least for the first combustion in at least one cylinder of the internal combustion engine during a cold start phase, the fuel injected into the cylinder being brought to combustion, and the method sets the spark angle to normal, to end the cold start phase.

Abstract: A method is provided for operating a spark ignition internal combustion engine having fuel injection at a cold start. The method retards the spark angle to a cold start value at least for the first combustion in at least one cylinder of the internal combustion engine during a cold start phase, the fuel injected into the cylinder being brought to combustion, and the method sets the spark angle to normal, to end the cold start phase.

Abstract: A method for influencing the exhaust gas temperature of an internal combustion is described in which measures can be carried out for increasing, lowering and limiting exhaust gas temperature. Depending on temperature requirements, and in which method these temperature requirements are prioritized, the temperature limitation having the highest priority for ensuring protection of the component parts, the resulting temperature requirement may be achieved by heating measures or cooling measures in such a way that heating measures and cooling measures are not applied at the same time.

Abstract: A fuel supply system for an internal combustion engine, particularly of a motor vehicle, includes a control unit for determining a fuel quantity to be injected, the fuel quantity to be injected being initially increased during a start of the internal combustion engine and then being reduced again. The fuel supply system also includes a fuel injector for injecting the fuel quantity to be injected into a combustion chamber. It is checked by the control unit whether a combustion has taken place in the cylinder, and, if no combustion has taken place, the fuel quantity to be injected is not reduced, or is not reduced to the same extent as when a combustion has taken place.