The power transmitted during actual driving is an important parameter for quantifying the efficiency of drivetrains. The driving power is calculated from the torque and speed of the shaft. The Dx-Power system makes mechanical power measurements on axles and shafts as simple as child's play. The system does not require an additional stator or reference point. The sensor unit (Dx-SCT) is mounted directly on the vehicle axle using a half-shell housing. There it records the torque (via strain gauges) and the speed via an integrated rpm sensor. The measured data are telemetrically transmitted to the Dx receiver unit (RCI) inside the vehicle. The receiver unit calculates the synchronous values of the two signals in real time according to the formula Power = Torque x Speed and displays all values in physical amounts.