Method and device for operating a drive unit

A device for operating a drive unit having an engine and a transmission, operation of the engine taking place using a first number of active cylinders in a first operating state and using a second number of active cylinders in a second operating state, the first number being different from the second number, the device comprising:

• a setting unit configured to set a gear ratio as a function of at least one operating variable of the drive unit, the setting unit further adapted to set the gear ratio as a function of a current or attainable operating state of the engine with respect to the number of the active cylinders according to an optimization criterion, so that, at a same value for an output variable of the drive unit with respect to the optimization criterion, optimum values come about for the at least one operating variable of the drive unit and the current or the attainable operating state of the engine with respect to the number of the active cylinders;
• and
• a checking unit to determine whether the gear ratio is able to be set at which, at a same value for the output variable of the drive unit, the at least one operating variable assumes a value at which the engine is operated in the first operating state;
• wherein in response to a positive checking result the gear ratio is set, the gear ratio being set independently of the current or the attainable operating state of the engine with respect to the number of the active cylinders in response to a negative checking result.

A device for operating a drive unit, the device comprising:

• a transmission;
• an engine, operation of the engine taking place using a first number of active cylinders in a first operating state and using a second number of active cylinders in a second operating state, the first number being different from the second number;
• a setting unit configured to set a gear ratio as a function of at least one operating variable of the drive unit, the setting unit further adapted to set the gear ratio as a function of a current or attainable operating state of the engine with respect to the number of the active cylinders according to an optimization criterion, so that, at a same value for an output variable of the drive unit with respect to the optimization criterion, optimum values come about for the at least one operating variable of the drive unit and the current or the attainable operating state of the engine with respect to the number of the active cylinders;
• and
• a checking unit to determine whether the gear ratio is able to be set at which, at a same value for the output variable of the drive unit, the at least one operating variable assumes a value at which the engine is operated in the first operating state;
• wherein in response to a positive checking result the gear ratio is set, the gear ratio being set independently of the current or the attainable operating state of the engine with respect to the number of the active cylinders in response to a negative checking result.