This book provides an introduction to ground vehicle aerodynamics and methodically guides the reader through the various aspects of the subject. Those needing specific information or a refresher can easily jump to the material of interest. There is a particular emphasis on various vehicle types (passenger cars, trucks, trains, motorcycles, race cars, etc.). However, the book is focused on cars and trucks, which are the most common vehicles in the speed range in which the study of ground vehicle aerodynamics is beneficial. Readers will gain a fundamental understanding of the topic, which will help them design vehicles that have improved aerodynamics; this will lead to better fuel efficiency, improved performance, and increased passenger comfort. The author’s basic approach to the presentation of the material is complemented with review questions, application questions, exercises, and suggested projects at the end of most of the chapters, which helps the reader apply the information presented, either in the classroom or for self-study. Aside from offering a solid understanding of ground vehicle aerodynamics, the book also offers more thorough study of several key topics. One such topic is car-truck interaction, when one vehicle (usually the smaller one) is overtaking the other. There is a direct and instant benefit in terms of safety on the highway from understanding the forces at play when one vehicle passes the other in the same direction and sense.