Combustion engine

An internal combustion engine (ICE) is a heat engine in which the combustion (of typically hydrogen and oxygen) occurs in a combustion chamber where heated gas expands and applies direct force typically to pistons, turbine, rotors, or nozzles. This force moves the component, transforming chemical energy into useful work in a wheel axle for example.

In contrast, in external combustion engines, such as steam engines, energy is delivered to a medium such as air, or hot pressurized water heated in a boiler. This was old technology and was replaced by ICE.

ICEs are usually powered by energy-dense fuels such as gasoline or diesel fuel, liquids derived from fossil fuels. Renewable fuels like biodiesel or bioethanol also also used and commonly blended with fossil fuels. This is the dominant power supply for vehicles such as cars, aircraft and boats for Type 0.