Automobiles are vehicles for human transport on land, powered by an internal combustion engine fueled by fuel oil, petroleum (petroleum), or other liquid fuel. They usually have four wheels and a chassis, and their design is based on the principles of aerodynamics, control systems, and mechanical engineering. Aesthetics and comfort are also important design factors.

The modern automobile is one of the most significant inventions of the 20th century, arguably having had a bigger impact than any other technology of that time. It has transformed people’s lives and enabled them to connect with each other in ways that were not possible before. It has contributed to the development of many other industries and has allowed humans to make use of the surplus of fossil fuels on the planet.

While the earliest cars were steam-powered, it was Nicolaus Otto and Gottlieb Daimler who perfected the internal combustion engine, which made the automobile a reality. They created the 1901 Mercedes, considered the first true modern motorcar. The design was light and nimble with a top speed of fifty-three miles per hour. Its price was within the reach of middle-class Americans, and its production exceeded any previous record.

The automobile became the backbone of a new consumer goods-oriented society. Its economic significance was so great that by the 1920s it ranked as America’s single most valuable industry and the leading employer of workers in manufacturing, construction, and service occupations. It also accounted for a large share of the nation’s consumption and consumed raw materials like steel, rubber, and gasoline. Despite these positives, the automobile has also become the cause of numerous negative and dangerous problems for society. Air pollution, climate change, and the draining of dwindling global oil reserves are among these problems.