By utilizing the exhaust energy from the combustion engine (waste energy recovery measure) in range extenders, plug-in hybrids, and commercial hybrid vehicles, the range of the vehicles is improved by increasing the overall efficiency of the powertrain. The exhaust enthalpy of the range extender is utilized by using a customized exhaust turbine with a directly coupled high-speed generator in the speed range up to 180,000 rpm. The key innovation of the proposed project lies in the further development and verification of the basic electric machine concept and its integration into a plug-in hybrid vehicle. Increasing the speed capability of the electric machine (electric motor/generator) to values used in regular turbocharger units enables the thermodynamic and fluid mechanical adaptation of the turbine for high efficiency and reduces the weight and installation space of the secondary power generation unit through previously unattainable power densities of the generator. As a result, it is now possible for the first time to integrate an electric exhaust gas compound expander into passenger cars, such as those currently in use in the first generation of e-mobility. In combustion engine operation of the hybrid vehicle, improvements in effective efficiency of around 5% are theoretically possible. The mechanical energy decoupled from the combustion engine for power generation for battery charging purposes can be increased by around 10%.