Turbocharging has become a recognized means of increasing the power output of gasoline and diesel passenger car and commercial engines. The application of turbochargers involves the consideration of many factors in the engine and vehicle systems. The optimization of these systems requires wide knowledge and experience in turbomachinery, engine design, performance analysis, emissions, and reliability. Various new technologies are continually being developed to improve the potential of engine boosting. Discussed herein are some of the history, application and performance of turbochargers. Advantages and disadvantages of various systems are presented, as well as state-of-the-art developments.