Automobiles are self-propelled motor vehicles designed for transporting people and goods. They are commonly powered by an internal combustion engine that uses a volatile fuel, typically gasoline (petrol). The modern automobile is a complex technical system with numerous subsystems and thousands of component parts that have evolved from breakthroughs in existing technology.
The modern car is an extremely important part of our everyday lives. It enables us to get to work and home, visit friends, go shopping and have fun. Without cars, our lives would be very different. The automobile is a very expensive and highly polluting means of transportation, but it also provides a great deal of freedom and mobility. It can be a very convenient mode of transportation in the city and country, but it is not ideal for long distance travel due to its speed limitations and environmental impacts.
Several hundred years ago, the automobile was a novelty. People traveled by horse, train or ship. But when Henry Ford developed the Model T, a low-cost, reliable, gas-powered, four-wheeled vehicle, automobiles became a major part of the economy. It gave millions of middle-class Americans the ability to work and play away from home, resulting in new services like motels, restaurants and fast food outlets.
Today, the automobile has become the most widely used means of transportation in the world. It has transformed our culture and our cities. Entire societies have restructured themselves around the power of rapid, long-distance movement and the flexible distribution of goods made possible by trucks and cars. The automobile has brought great convenience to most of humanity, but it has also contributed to urban sprawl and degraded natural resources. The pollution caused by gas-burning engines has led to new laws and government requirements, such as seat belts and highway rules.
Automobiles are classified according to their load-carrying capacity and the type of engines they use. They are usually categorized as light motor vehicles (LMV) — cars, jeeps, minivans, etc., medium motor vehicles (MMV) — buses, mini trucks and so on, and heavy motor vehicles (HMV) — truck, trailers, containers and multi-axle bus.
An automobile is a large, heavy machine with many moving parts that must function in harmony. Much like the human body, an automobile is organized into semi-independent systems, with each system serving a particular purpose. For example, the engine has a circulatory system for coolant, lubricating oil and fuel. There is an electrical system to start the engine and a battery to supply energy to operate the computer control system. In addition, the suspension system has springs and shock absorbers that support the chassis over the wheels. There are a number of different types of suspension, including Mac person strut and wishbone. In most cases, the suspension system on a vehicle is independent, meaning that when one wheel hits an obstacle there is no influence on the other wheels. But some vehicles have non-independent suspension, in which the opposite wheel may move upwards or downwards.