Few inventions in modern times have had as large an effect on society and the economy of the world as the automobile. It has allowed people to travel long distances and move to different jobs and places. This freedom has brought with it leisure activities and new services like restaurants and convenience stores. The automobile has also led to changes in the environment through pollution and the use of undeveloped land for highways.
The development of the automobile began in the late 1600s with designs by Leonardo da Vinci. By the 19th century, steam, electric power and gas engines had been developed and the first automobiles were made. Gasoline engines became the most popular form of motor car. Unlike horse-drawn carriages, which could only travel a short distance and were difficult to start, gasoline engines were easily started and had greater top speeds. Today, there are more than five hundred million automobiles in the world and over two billion on the roads.
Modern automobiles are complex technical systems involving many interrelated parts. The design and arrangement of these parts is determined to a large degree by the type and use of the automobile. For example, a car intended for off-road driving requires durable systems that are resistant to severe overloads and operating conditions. On the other hand, a high-performance vehicle needs optimized handling and engine performance.
The basic components of all automobiles include the engine, fuel system, transmission, cooling and lubrication systems, electrical system and chassis. Thousands of individual parts are arranged into semi-independent systems, just as the human body has several different circulatory systems that function together to perform the same vital functions.