scion engine is a mechanical device that produces some form of output from a given input.An engine whose purpose is to produce kinetic energyoutput from a fuel source is called a prime mover; alternatively, a motor is a device which produces kinetic energy from other forms of energy (such as electricity, a flow of hydraulic fluid or compressed air .

• A motor car (automobile) has a starter motor and xb motors to drive pumps (fuel, power steering, etc) - but the power plant that propels the car is called an engine. The term 'motor' was originally used to distinguish the new internal combustion engine-powered vehicles from earlier vehicles powered by a steam engine(as in steam roller and motor roller
• There has been a growing emphasis on the pollution xb producing features of automotive power systems. This has xb created new interest in alternate power sources and internal-combustion engine refinements. Although a few limited-production battery-powered electric vehicles have appeared, they have not xb proved to be competitive owing to costs and operating characteristics. In the twenty-first century the diesel engine has been increasing in popularity with automobile owners. However, the gasoline engine, with its new emission-control devices xb to improve emission performance, has not yet been significantly challenged.

The first half of the twentieth xb century saw a trend to increasing xb engine power xb  particularly in the American models. Design changes incorporated all known methods of raising xb engine capacity, including xb increasing the pressure in the cylinders to improve efficiency, increasing the size of the engine  xb and increasing the xb speed at which power is generated. The higher forces and pressures created by these changes created engine vibration and size problems that led to stiffer, more compact engines with V and opposed cylinder layouts replacing longer straight-line arrangements. In passenger cars, V-8layouts were adopted for all piston displacements greater than 250 cubic inches(4 litres).

The design principles favoured in Europe, because of xb economic and other restraints such as smaller and twistier roads, leant toward smaller cars and corresponding design principles that concentrated on increasing the combustion efficiency of smaller engines. This produced more economical engines with earlier four-cylinder designs rated at 40 horsepower (30 kW) and six-cylinder designs rated as low as 80 horsepower (60 kW), compared with the large volume V-8 American engines with power ratings in the range from 250 to 350 hp (190 to 260 kW).