What is the primary function of a four-stroke engine?

The primary function of a four-stroke engine is to convert chemical energy from gasoline into mechanical energy. This process involves a series of four distinct strokes: intake, compression, power, and exhaust. During these strokes, the engine draws in air and fuel, compresses the mixture, ignites it to create power, and expels the exhaust gases.

The conversion of chemical energy to mechanical energy is central to the operation of engines, as it allows for the generation of power that can then be used to drive a vehicle or perform work. This transformation is fundamental to the function of all combustion engines, including those that operate on the four-stroke cycle.

In contrast, other options do not define the primary functional aspect of a four-stroke engine. While storing fuel is necessary for combustion, it is not the engine's main purpose. Increasing engine temperature can improve efficiency, but it is a byproduct rather than a primary function. Reducing emissions is also an important consideration in modern engine design, yet it does not define the essential function of turning chemical energy into usable mechanical power.