Automobiles are four-wheeled, motor vehicles designed primarily for passenger transportation and powered by an internal combustion engine using a volatile fuel. The modern automobile is a complex technical system, comprising numerous subsystems with specific design functions. It is a significant consumer of petroleum products and one of the major consumers of steel and other nonferrous metals. It is also a major contributor to air pollution and a serious drain on the world’s dwindling oil reserves.
Modern automobiles run on gasoline, diesel fuel, kerosene or other hydrocarbons that are burned in an engine to produce the energy to move the vehicle and its passengers. The power from the engine is transmitted to the wheels through a transmission.
Cars come in a variety of shapes and sizes. Some are smaller and more nimble than others. They may be sedans, hatchbacks, station wagons, coupés or minivans. Some are rugged and carry cargo in addition to people. Others are primarily sports cars or luxury models. Many of the newer vehicles are hybrids, which combine a conventional gasoline or diesel engine with an electric motor for improved fuel efficiency.
Having a car means you don’t have to rely on other people or public transportation to get where you want to go. But owning a car can be expensive. And it doesn’t always make sense if you live in an area with limited or no bus, train, tram or subway options. For these reasons, a car can be more of a burden than an asset.