Method for determining the composition of a fuel mixture

Use of a combustion engine to determine a composition of a gasoline/ethanol-fuel mixture, a gasoline/methanol fuel mixture, a gasoline/ethanol/methanol fuel mixture, for the differentiation of a diesel fuel and a biodiesel fuel, or for the detection of a combustion engine malfunction by implementation of a method of determining the composition of a fuel mixture from a first and at least a second fuel for the operation of a combustion engine, whereby fuel mixtures of different compositions require various air-fuel ratios in order to achieve a stoichiometric combustion, the method comprising:

• determining an oxygen content value of an exhaust gas during one or more measuring phases of one or more stationary operating phases;
• determining an air volume value delivered to the combustion engine during the one or more measuring phases;
• determining a fuel volume value delivered to the combustion engine during the one or more measuring phases;
• and
• determining a fuel mixture composition from the oxygen content value, the air volume value, and the fuel volume value.

Use of a combustion engine to facilitate the adaptation of one or more combustion engine operating parameters to a present composition of a fuel mixture by implementation of a method of determining the composition of a fuel mixture from a first and at least a second fuel for the operation of a combustion engine, whereby fuel mixtures of different compositions require various air-fuel ratios in order to achieve a stoichiometric combustion, the method comprising:

• providing one or more stationary operating phases of the combustion engine;
• providing one or more measuring phases of the combustion engine occurring during the one or more stationary operating phases;
• determining an oxygen content value of an exhaust gas during the one or more measuring phases;
• determining an air volume value delivered to the combustion engine during the one or more measuring phases;
• determining a fuel volume value delivered to the combustion engine during the one or more measuring phases;
• and determining a fuel mixture composition from the oxygen content value and the air volume value and the fuel volume value.