Over the last few years, hybrid electric vehicles have taken significant role in automotive market. There are successful technological solutions of hybrid-electric propulsion systems implemented in commercial passenger cars. Every automobile manufacturer of hybrid vehicles has unique hybrid propulsion system. In this book, all implemented systems are described, analysed and compared. Despites that each company implements different technologies, the common feature to all are that their commercial success is strictly related to the control system of the propulsion system. Good car-hybrid control strategy results with vehicles low fuel consumption, which is main reason for implementation of hybrid-electric technology and its commercial success. This book explains the solution for creation of control system for hybrid cars of the current concepts and newly developed one. Entire experimental approach is described for testing newly developed hybrid-electric propulsion system within laboratory conditions without constructing actual vehicle.