Fundamentals of Internal Combustion Engines focuses on the gradual transition from the theoretical concepts of Engineering Thermodynamics to one of its applied counterparts - combustion engines. Accordingly, a few initial chapters have been devoted to recapitulation of thermodynamics principles while the rest are centered on the development of the subject proper. A blend of the classical knowledge and modern concept supported by ample experimental evidence, particularly in the field of combustion in SI and CI engines, is the crux of the book. Important areas like fuels, materials, equipment for engine performance measurement etc. have also been adequately addressed. Some aspects of gas turbine have also been discussed in brief.