Automobiles are wheeled vehicles designed primarily for passenger transportation and commonly powered by internal combustion engines that burn fuel to make the car move. Most modern automobiles have four wheels and can seat one to seven people. Most are equipped with a transmission and can be driven on roads or off. The automotive industry grew rapidly in the United States after 1900 as more middle-class families could afford to buy cars. This expansion of personal transport led to a boom in the economy and brought changes to society and the environment as well.

There are many different types of automobiles, from luxury models that cost a lot to cheap vehicles that can be used for work or just running errands. There are also special automobiles for emergencies, like fire trucks and ambulances. In addition to passenger automobiles, there are also commercial automobiles that carry goods from place to place. There are even automobiles that are designed to help in construction or as crane vehicles in warehouses.

The history of the automobile began with the invention of the steam engine in the late 1600s. Then, in the early 1800s, the German inventor Karl Benz invented the first practical gas-powered automobile. Eventually, these vehicles became very popular in the United States and replaced horse-drawn carriages.

During the first half of the twentieth century, American manufacturers dominated the automobile industry. Henry Ford innovated mass production techniques that enabled him to produce the Model T, and General Motors, Chrysler and Ford all made a fortune during this time. However, the companies were unable to keep up with demand for automobiles during World War II, and they funneled most of their resources into military production. The industry then declined.

In the 21st century, the automobile continues to be very popular worldwide. There are many reasons for this, including the fact that it is more affordable than ever before. However, there are also some drawbacks, such as air pollution and the impact on dwindling oil supplies. In order to limit the damage, governments have enacted laws that require automobiles to be safe and environmentally friendly.

In urban areas, most automobiles are powered by gasoline or diesel, which is burned inside an internal combustion engine that turns a crankshaft to drive the wheels. The exhaust from this engine is then expelled through a pipe, which goes to the tailpipe of the vehicle. Other emissions may include nitrogen oxide and particulates. These chemicals can lead to smog and global warming. In order to control these problems, there are a number of ways that people can reduce their use of automobiles. Some of these options include carpooling, walking or using public transportation. There are also some automobiles that run on other kinds of fuel, such as electricity and battery power. There are also hybrid automobiles that run on both types of fuels. These are more efficient than regular automobiles, but they still produce some carbon dioxide and other pollutants.