Automobiles are vehicles designed to carry people, typically with four wheels and a chassis that is attached to an engine and transmission system. They are powered by internal combustion engines fueled by a volatile fuel. The modern automobile has a complex design with thousands of parts. The individual components are organized into systems with specific design functions. These systems are modeled after the human body, with circulatory systems for coolant fluid and lubricating oil, as well as the heart of the automobile, the internal combustion engine.
The automobile has had a tremendous impact on society over the past century. It has radically changed the way people live, work and play. It enables the rapid movement of people over long distances and allows individuals to choose where they want to live in relation to their jobs. It has reshaped cities and has allowed them to grow into sprawling low-density communities. Automobiles are the foundation of the transportation industry and have greatly influenced retailing, the distribution of goods and services, and the use of labor-saving technologies such as assembly-line production.
The most important parts of an automobile are the engine, suspension system and chassis. The chassis is the skeleton of the automobile and supports the engine, the transmission system and the car body. The engine has from four to eight cylinders, each of which is driven by the crankshaft. The number of cylinders determines the power of an automobile, and each cylinder operates in a cycle that includes an intake stroke, compression stroke and exhaust stroke. The transmission system is a set of gears that convert the engine’s rotational speed to wheel-speed.