Motor For the record company, see Motor Music Records. Jet engine 1915, with available water-cooled radial. V12 Motor car used in a Lamborghini Murcielago. An engine is part of a machine capable of transforming any type of energy (electricity, fossil fuels …), into mechanical energy capable of performing a job. On cars this effect is a force that produces motion. There are different types, being the most common: heat engines, where the work is derived from thermal energy. Internal combustion engines are heat engines in which combustion occurs in the working fluid, changing its chemical energy into heat energy, from which mechanical energy is obtained. The working fluid before starting the combustion is a mixture of an oxidizer (like air) and fuels such as petroleum, natural gas prices and biofuels.External combustion engines are heat engines in which combustion occurs in a fluid other than the working fluid. The fluid heat engine reaches a higher energy state by transferring energy through a wall. Electric motors, where work is derived from an electrical current. In the wind, hydroelectric or nuclear reactors also becomes some kind of energy into another. However, the word motor is reserved for cases in which the immediate result is mechanical energy.