The book provides a comprehensive overview of the development status and trends in automotive exhaust catalytic systems up to Euro 5. It particularly highlights the complex interplay of many components and disciplines involved in the catalyst, without which continuous development and adaptation to new conditions (legislation, engine concepts, fuel qualities) would not be possible. Authors from renowned companies involved in the catalytic system clearly explain the function, significance, and production of individual components - from the catalyst carrier to coating, canning, and control electronics, as well as the tuning of the overall system at the vehicle manufacturer. Results are presented based on field measurements from the Swiss Touring Club. Additionally, aspects such as precious metal markets, ecological balance, catalyst recycling, and platinum metal emissions are addressed.