Basics of Automotive Systems

LEARNING GOALS

• +++Explain the major events that have influenced the development of the automobile during the last 50 years.
• +++Explain the difference between unitized vehicles and body-over-frame vehicles.
• +++Describe the manufacturing process used in a modern automated automobile assembly plant.
• +++List the basic systems that make up an automobile and name their major components and functions.

|||| The 1886 Benz Patent Motor Wagen, one of the first automobiles made.

SOME HISTORY

The automobile has changed quite a bit since the first horseless carriage went down an American street. In 1896, both Henry Ford and Ransom Eli Olds test drove their first gasoline-powered vehicles. Prior to this time, other individuals were making their own auto mobiles ---. Most were powered by electricity or steam. The year 1896 marks the beginning of the automotive industry, not because of what Ford or Olds did, but because of the Duryea Brothers, who, by 1896, had made thirteen cars in the first factory that made cars for customers.

In the beginning, the automobile looked like the horse-drawn carriage it was designed to replace. In 1919, 90% of the cars had carriage-like open bodies.

These early cars had rear-mounted engines and very tall tires. They were designed to move people down dirt roads.

The automobile changed when the roads became paved, more people owned cars, manufacturers tried to sell more cars, concerns for safety and the environment grew, and new technology was developed.

All of these changes resulted in automobiles that are more practical, more affordable, safer, more comfort able, more dependable, and faster. Although many improvements have been made to the original design, the basics of the automobile have changed very little:

• +++Nearly all of today's cars still use gasoline engines to drive two or more wheels.
• +++A steering system is used to control the direction of the car.
• +++A brake system is used to slow down and stop the car.
• +++A suspension system is used to absorb road shocks and help the driver maintain control on bumpy roads.
• +++These major systems are mounted on steel frames and the frame is covered with body panels.
• +++The body panels give the car its shape and protect those inside from the weather and dirt.
• +++The body panels also offer some protection for the passengers if the automobile is in an accident.
• Although these basics have changed little in the past 100 years, the design of the systems has greatly changed. The entire automobile is technologically light-years ahead of Ford's and Olds's early models.

New technologies have changed the slow, unreliable, user-hostile vehicles of the early 1900s into vehicles that can travel at very high speeds, operate trouble free for thousands of miles, and provide comforts that even the very rich had not dreamed of in 1896.

Social and political pressures have had a great influence on automobile design for the past 40-plus years. In 1965, laws were passed that limited the amount of harmful gases emitted by an automobile.

Although this had little immediate effect on the industry, the automobile manufacturers were forced to focus on the future. They needed to build cleaner burning engines. In the following years, stricter emissions laws were passed and manufacturers were required to develop new emission control systems.

World events in the 1970s continued to shape the development of the automobile. An oil embargo by Arab nations in 1973 caused the price of gasoline to quickly increase to four times its normal price. This event caused most Americans to realize that the sup ply of gasoline and other nonrenewable resources was limited. Car buyers wanted cars that were not only kind to the environment but that also used less fuel.

The Corporate Average Fuel Economy (CAFE) standards were set in 1975. These required automakers to build more fuel-efficient vehicles. Under the CAFE standards, different models from each manufacturer are tested for the number of miles they can be driven on a gallon of gas. The fuel efficiencies of these vehicles are averaged together to arrive at a corporate average. The CAFE standards have increased many times since it was established. A manufacturer that does not meet CAFE standards for a given model year faces heavy fines.

While trying to produce more fuel-efficient vehicles, manufacturers replaced large eight-cylinder engines with four-cylinder and other small engines.

Basic engine systems like carburetors and ignition breaker points were replaced by electronic fuel injection and electronic ignition systems.

By the mid-1980s, all automobiles were equipped with some type of electronic control system. These systems did, and still do, monitor the engine's operation and provide increased power outputs while minimizing fuel consumption and emissions. Electronic sensors are used to monitor the engine and many other systems. Computerized engine control systems control air and fuel delivery, ignition timing, emission systems operation, and a host of other related operations. The result is a clean-burning, fuel-efficient, and powerful engine.

|||| Example: A cutaway of a late-model V-10 gasoline engine.

Next: Evolution of Design; Body Shapes

Prev.: Shop skills--Terminology, Summary, Exam