The fast growth in world population and the associated energy requirements, the announced depletion of fossil fuel resources, the continuing rise in greenhouse gas (GHG) emissions with the induced climatic changes represent some of the major challenges to be taken up in the coming years and decades. I Hybridization therefore typically represents a transition technology which can significantly improve the energy and environmental performance of current vehicles, without radically changing their use typologies, while opening the way to new propulsion modes for the longer term. It is nevertheless a complex subject requiring a multidisciplinary approach. This book, which is intended to be exhaustive, considers the vehicle, its components, their association and their control, as well as the global balances determined over the vehicle lifetime. It starts with a general presentation of the various conditions of use of vehicles, to give readers an understanding of the stakes related to the development of hybrid vehicles and the methods used to compare the performance of the various solutions. The principles and the various types of internai combustion engine and electrical drives, onboard energy storage systems, principles, architectures, specific components and operation of hybrid drivetrains, as well as the energy management in these vehicles, are developed. A global analysis of the various drivetrains, life cycle assessment (LCA), total costs and availability of sensitive materials is also provided. This book is intended for everyone involved in the design, manufacture and implementation of hybrid drive vehicles and their components. It will also be of interest to students, teachers and researchers wishing to acquire or further their knowledge in ail fields impacted by drivetrain electrification. More globally, after consulting this book, readers will be in a position to evaluate the technologies related to the concept of drivetrain hybridization, their implementation, balances and generalization conditions.