The electrification of the powertrain is still one of the main challenges and innovation drivers for modern cars. With the introduction of the Toyota Prius, launched in Japan in 1997 the first commercially available hybrid car in mass production, the development continued towards the BMW i3 launched in July 2013.One main component for all kind of hybrid cars is still the power semiconductor, which is used for DC/DC converters and for the inverter to drive the electric motor for the traction control. What makes the selection of the right power semiconductor complex, is the variety of different voltage levels within the car (from standard 12V board net, the new 48V board net all the way up to 400V and above) plus different requirements in terms of switching and conduction performance, or accordingly power losses.The selection of device by application and voltage will be discussed in this paper. By comparing and contrasting the technology differences of MOSFETs and IGBTs, a recommendation for the ideal power device for different applications will be given. Typical trade off diagrams including switching frequency and breakdown voltage will help the designer to select the right device at a glance.