Automobiles are four-wheeled vehicles that have become the main mode of transportation in much of the world. They are generally propelled by an internal combustion engine that uses gasoline, diesel fuel, or kerosene to operate. The exploded fuel then turns the crankshaft, which drives the wheels that roll over the road. Depending on the model, the car may also carry passengers or cargo. The automobile has had a significant influence on human society and culture in modern times.
Few inventions have changed the lives of humans as dramatically as the automobile has. It has enabled people to live more active lifestyles and to visit distant places they could not reach by foot or horseback in the past. It has also reshaped the economic and political landscape of the developed world. It has contributed to a great increase in personal freedom and created new industries that make and service cars. It has also brought new social problems, however, including environmental degradation and traffic congestion.
In the late 1860s, Siegfried Marcus in Vienna, Austria, began developing two-stroke internal-combustion engines. In 1870, he built the first automobile, a crude vehicle without seats, steering, or brakes that used a handcart to pull a three-horsepower, one-cylinder, three-horsepower gasoline engine. Karl Benz in Germany then constructed the first automobile with a permanent chassis and four-stroke engine. He produced several models in a factory and started selling them in 1888. Benz’s success encouraged other manufacturers, such as Ransom Olds in the United States, to develop automobiles that were powered by gasoline.
As the auto industry grew in the early 1900s, the price of cars came down. Henry Ford’s innovation of assembly line production revolutionized industrial manufacturing, and his Model T runabout sold for less than the average annual wage in 1912.
After the Great Depression, automakers turned their attention to producing economical small cars. This led to a huge increase in the number of automobiles on the roads. By the 1970s, the automobile had become the primary mode of transportation in most countries. Its popularity is based on the convenience of driving, the ability to carry large loads of goods, and the freedom it gives to individuals to travel long distances.
Most of today’s cars are powered by gasoline, which releases carbon dioxide, a greenhouse gas, into the atmosphere when it burns. The United States Environmental Protection Agency estimates that transportation accounts for 27 percent of the nation’s greenhouse gas emissions. In the future, some experts believe that hybrid electric vehicles and alternative fuels may be able to reduce these emissions.