Method for adjusting a vehicle speed and control system for engine and/or gearbox of a vehicle

The method involves detecting a gas pedal (7) position, detecting a set speed value of a speed governor, detecting a manually set desired acceleration mode of the speed governor, computing a desired acceleration depending on the gas pedal position, the set speed value and the set mode, estimating a value of at least one operating parameter required to achieve the desired acceleration and setting the computed operating parameter(s). An independent claim is also included for a control circuit for a motor and/or gearbox of a motor vehicle for implementing the inventive method.