The textbook provides a brief basics of technical thermodynamics and the theory of working processes occurring in automotive internal combustion engines, as well as an analysis of factors affecting the course of the working process, engine power and efficiency. The characteristics of automobile engines, the basis of the carburation process in spark ignition engines and data on fuel supply equipment and mixture formation processes in diesel engines are given. Brief information on engine test methods and instruments used for this purpose is given. The basics of kinematics and dynamics of the crank mechanism are presented and the designs of automobile engines (their main parts, gas distribution, cooling and lubrication systems) are considered. The textbook is intended for students of automobile and road technical schools in the specialty "Maintenance and repair of cars."