Automobiles are four-wheeled vehicles designed to carry passengers and propelled by an internal combustion engine using a volatile fuel. They are among the most complex inventions in modern history, with thousands of parts arranged into systems with specific design functions. These system designs evolved from breakthroughs in science and technology as well as from environmental requirements and competition among manufacturers worldwide.
The basic components of an automobile are the engine, which converts chemical energy from gasoline into mechanical energy to turn the wheels, and the suspension system, which allows the car to respond to bumps and variations in road surface conditions. An automobile needs to have the energy to start moving, which may come from electrical systems that recharge the battery and power the motor or from the energy stored in its gasoline tank. It also must have a way to stop and steer, which are controlled by an electric system.
Most cars use a gasoline-powered internal combustion engine to propel them. The engine uses a mixture of gasoline, air and oil, ignited by spark plugs, to push down on the piston, turning the wheels. The wheels are connected to the engine by a system of tires and rims. The suspension system uses springs to absorb shocks and vibrations from the road.
Many different kinds of automobiles have been developed to suit people’s individual tastes and needs. For example, some people like coupes (coupés in American English), which have two doors and are viewed as sportier than sedans. Other people prefer station wagons, which combine passenger and cargo space, or vans, which are used to carry large amounts of luggage and equipment. Having a car gives families the ability to travel together in safety and comfort. It also provides a level of independence that public transportation cannot match.