Automobiles are vehicles that can transport people or things. They are usually four-wheeled and powered by an internal combustion engine that burns a volatile fuel such as petrol or diesel. The automobile is a complex technical system that comprises thousands of component parts that have specific design functions. Its subsystems include body, chassis, engine and transmission system, driving systems, control systems and auxiliary systems.
Cars are an indispensable means of transportation in modern society. They can take us from place to place much faster than walking or riding bikes, and they are capable of carrying more luggage than those modes of transport. They can also go places that are inaccessible to other wheeled vehicles such as buses, trains and trams. However, they can also be expensive and polluting.
The history of the automobile is long and varied, and its impact on the world has been profound. There have been many different types of automobiles, from steam to electric to gasoline-powered. In the early 20th century, industrial manufacturing methods introduced by American carmaker Henry Ford dramatically reduced the price of cars, making them more affordable for middle-class families.
Automobiles are generally propelled by an internal combustion engine that uses a volatile fuel such as petrol or diesel, but there is also an increasing interest in electric power and hydrogen vehicles. Depending on the fuel used, automobiles emit pollution that contributes to climate change and air quality issues in urban areas. Moreover, automobiles can be very dangerous for people when they crash.
Historically, most automobiles have been made with steel and metal, but recent technological advances in lightweight materials have produced vehicles that are more environmentally friendly and safer to drive than ever before. These new lightweight materials include carbon fiber, aluminum, and magnesium. In addition, advanced safety features such as airbags, electronic stability control and anti-lock braking systems have become standard on most automobiles.
A typical passenger automobile has seating for up to five passengers. Vehicles with more than seven seats are normally described as limousines, minivans or vans. Passenger automobiles are the majority of vehicles in use, with 1.4 billion in operation worldwide. Passenger cars are often more comfortable and convenient to ride in than trucks or other vehicles, and they can also be more economical to operate since they are typically driven at lower speeds.