An automobile is a type of vehicle that is used to travel on land. It usually has four wheels and an internal combustion engine that is fueled by gasoline, a liquid petroleum product.
Automobiles can be designed to suit a variety of purposes and use conditions, and many are built for speed. They are typically accompanied by an extensive suspension system, which is the system that allows the automobile to absorb the shocks and variations in the road surface that occur while driving.
The invention of the automobile has had a profound impact on the world, influencing the way in which people live and move around. However, the development of the automobile also created a number of social problems, such as traffic congestion, air pollution, and road rage.
In the United States, automobiles became the dominant form of transportation in the first half of the twentieth century, transforming American society and encouraging urban sprawl. Automobiles have facilitated rapid, long-distance movement and the flexible distribution of goods to consumers.
There is a wide range of vehicles, from small cars that carry only a few passengers to large passenger buses and vans. The size of an automobile is determined by its purpose and its required weight.
Almost every automobile is equipped with an internal combustion engine. These engines have been developed and perfected over time to provide a reliable, fuel-efficient means of transportation.
A typical engine has from four to eight cylinders, which work together in a sequence to turn the crankshaft. The number of cylinders that an engine uses depends on the size of the car and its power requirements.
Most automobiles have a front engine, which places the engine in the front of the vehicle over or ahead of the axle. This arrangement distributes the weight of the car evenly between the axles.
Some vehicles, such as trucks and buses, have a rear engine. This design distributes the load evenly between the axles and enables the vehicle to be more stable.
An engine can also be located in the center of a vehicle, as is the case in a pickup truck. This makes the engine more visible and convenient for the driver, but may require more space inside the vehicle and can reduce its overall weight.
Another type of engine is a water-cooled unit. This is more energy-efficient than a standard gas engine but has a limited number of cylinders.
In the United States, there are a few automobile manufacturers, including Ford, General Motors, and Chrysler. The Big Three monopolize the industry, and most independents have failed to survive. This is especially true after World War II, when the war effort prompted production to be shifted to military items.