Cars: An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor. Most definitions of the term state that automobiles are designed to run mainly on roads, to have seating for one to eight people, usually have four wheels, and to be constructed mainly for the transport of people rather than goods.
The word motorcar has also been used in the context of electrified rail systems to indicate a car which functions as a little train but also provides space for passengers and luggage. These trains cars were frequently used on suburban routes by both interurban and intercity railroad systems.
There are more or less 600 million passenger cars worldwide (roughly one car per eleven people). Around the world, there were about 806 million cars and light trucks on the road in 2007; the engines of these burn over a billion cubic meters (260 billion US gallons) of petrol/gasoline and diesel fuel annually. The numbers are increasing speedily, especially in China and India.