Automobiles are motor vehicles used for transportation. They typically have four wheels and are powered by internal combustion engines fueled most commonly by gasoline, but also by other fuels such as diesel, liquefied petroleum gas (LPG), or electricity. Most automobiles are designed to be driven on sealed roads, but some have been designed for off-road use or for driving in difficult terrain. Different automotive designs must consider passenger comfort, cargo capability, engine performance, aerodynamics, handling, and stability. Stability depends principally on the distribution of weight between the front and rear wheels, the height of the center of gravity and its position relative to the aerodynamic centre of pressure of the vehicle, and suspension characteristics.

The invention of the automobile has had a tremendous effect on society. It revolutionized industry and technology and made modern life possible in the United States. The automobile changed people’s daily lives and gave them freedom of movement that had never been available before. The automobile spawned industries that provided jobs and services such as oil and gas, rubber, and then plastics. Services like gas stations and convenience stores sprang up.

Before the automobile was invented, moving a short distance often meant a long buggy ride over rough roads. The invention of the automobile made it possible to travel for leisure and to visit cities and rural areas. This in turn led to the growth of suburban areas.

Although some inventors had developed steam-powered road cars in the 1860s and ’70s, it was Karl Benz who perfected the gasoline engine in 1900 and introduced his automobile to the public. Prior to this time, car production was limited because the vehicles were expensive and labor-intensive.

Ford revolutionized industrial manufacturing by using the assembly line, allowing him to produce one model with a few basic features and reduce the price of the automobile until it was affordable for most middle-class families. He also increased wages for his workers, which allowed more people to afford a car.

Today there are more than 1.4 billion cars in operation worldwide. They are primarily driven on streets and highways and carry more than three trillion miles (five trillion kilometers) each year. It is estimated that over 4.2 million people work directly in the automobile industry.

Some of the most important developments in automotive engineering have been the development of safety systems, power steering, automatic transmission, electric and electronic ignition, and air conditioning. New technical developments are being made constantly. Automobile manufacturers must keep up with these developments to stay competitive. Some of these include front-wheel drive, unibody construction, transverse engine positioning, and the use of advanced fuel injection systems. New technologies will be needed to address the effects of global warming and climate change, as well as to reduce the pollution caused by the manufacture and operation of automobiles. These issues will be the focus of future research. This will require a commitment to alternative energy sources, fuel efficiency, and improved safety.