Few inventions in modern times have had as much impact on the history, economy and social life of much of the world as automobiles. Whether you are driving to work or school, shopping or visiting family and friends, or simply running errands, having your own car can save you precious time and effort by allowing you to travel more quickly and independently.
Having your own car can also help you be more available for your children or family members in emergency situations. For instance, if your child becomes ill or has a problem at school, it is often difficult to get them home quickly when using public transportation. By having your own vehicle, you can make the trip in a few minutes and be there for them when they need you.
Automobiles are self-propelled vehicles that have four to eight tires and are powered by an internal combustion engine or electric motor. The branch of engineering that deals with the design and technology of these vehicles is called automotive engineering. The most common fuel for automobiles is gasoline, which is used to power the engines that turn the wheels of the car. Historically, some cars were powered by steam and electric energy. While steam-powered cars were powerful, they required a lengthy time to start, and the battery-powered electric cars of the early 1900s had only a limited range and made it impractical for most people to use them.
The major systems of an automobile include the engine, fuel system, transmission, electrical system, cooling and lubrication system, and chassis. The design of each of these systems, their relationship to one another, and their interaction with the rest of the automobile depend on the type and use of the vehicle. For example, an automobile designed for off-road driving requires durable and simple systems that are capable of withstanding extreme overloads. An automobile designed for high speed will require a more advanced suspension system and optimized steering and handling capabilities.
In addition to these systems, an automobile must have a structure that will hold the passengers and protect them in case of an accident. To achieve this, the body is built by welding together stamped components to form a complete unit. The safety of the passengers is further enhanced by a number of features, including strong crumple zones and a firewall between the engine and passenger compartment.
Automobiles come in many different shapes and sizes to suit various needs and tastes. Some are designed for comfort, such as sedans, hatchbacks and station wagons. Sport utility vehicles, such as SUVs and minivans, are designed for carrying lots of passengers and cargo. Others are built for performance, such as sports cars and racecars. And there are special purpose vehicles, such as police and fire trucks and ambulances. Regardless of the type or style of automobile, all must meet certain standards for safety and appearance. They must also have systems that control pollution and emissions, and be easy to drive and maintain.