Top 5 Materials Used in Auto Manufacturing

Some materials have long been used to build automobiles, but some new ones are also gaining ground in the industry. See more diesel engine pictures.
© Azoury

Have you ever wondered exactly what your car is made of? No, not how hard and fast it can be pushed on a race track, or what its limits off-road really are -- but what materials are actually used to build it.

We hear a lot about the parts that make up our cars, such as engines, transmissions, seats, HVAC systems, and so on. But we never really give much thought to the bits and pieces of raw materials that are used in auto manufacturing to create these things.


The car industry uses a tremendous number of materials to build cars, including iron, aluminum, plastic steel, glass, rubber, petroleum products, copper, steel and others. These parts are used to create everything from those small things we don't think about, such as dashboard needles and wiring, to the big stuff, such as the engine block or the transmission gears.

These materials have evolved greatly over the decades, becoming more sophisticated, better built, and safer. They've changed as new automotive manufacturing technologies have emerged over the years, and they're used in increasingly innovative ways.

In this article, we'll discuss five of the materials used most in automotive manufacturing. Up first, we'll take a look at the one that makes automobiles so heavy.

5: Steel

Steel is used to build the car's underlying frame of support.
© Vasily

On modern cars, most of the weight comes from steel. In 2007, for example, the average car contained 2,400 pounds (1,090 kilograms) of steel, and the average pickup truck or SUV used nearly 3,000 pounds (1,360 kilograms) [source: Sherefkin]. Consider that most cars now weigh around 3,000 pounds, and most SUVs weigh around 4,000 pounds (1,810 kilograms) -- that's a lot of steel!

In cars, steel is used to create the underlying chassis or cage beneath the body that forms the skeleton of the vehicle and protects you in the event of a crash. Door beams, roofs and even body panels created during auto manufacturing are made of steel on most cars today. Steel is also used in a variety of areas throughout the body to accommodate the engine or other parts. Exhausts are often made from stainless steel, for example.


Steel manufacturing has evolved greatly, so carmakers these days can make different types of steel for different areas of the vehicle that are rigid or that can crumple to absorb different impacts. These innovations in automotive manufacturing help keep you safe on the road [source: Fountain].

4: Plastic

Many parts of the dashboard, including gauges and dials, are created from plastic.
© J. Noskowski

The next time you're sitting inside your car, do like Dustin Hoffman's character did in "The Graduate" and think of one word: Plastics. Today's cars now use tremendous amounts of plastics in auto manufacturing. They make up about 50 percent of the construction of new cars today [source: American Chemistry Council]. It's not surprising because plastics are durable, cheap to make and can be turned into just about anything.

Your dashboard, gauges, dials, switches, air conditioner vents, door handles, floor mats, seat belts, airbags and many other parts are all made from different types of plastics.


In addition to the dashboard parts, many of the tiny parts inside the engine, such as the handle on the oil dipstick, are also made of plastic. Because of their lightweight nature, plastics are being increasingly used in body structures and in engines during automotive manufacturing.

3: Aluminum

Aluminum is used to make parts such as wheels and hubcaps.
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In the world of auto manufacturing, aluminum is kind of the new kid on the block. It's being used increasingly in the car world for its lightweight but tough nature. In 2009, aluminum components made up about 9 percent of the weight in most modern vehicles, compared with about 5 percent in 1990 and just 2 percent in 1970 [source: Aluminum Association].

Aluminum can be used in automotive manufacturing to create body panels for a lighter, more performance-oriented vehicle. Starting with the Acura NSX in the early 1990s, many supercars have been constructed out of aluminum, including the white-hot Audi R8. Wheels are also often made out of aluminum.


In addition, more automakers are switching from traditional iron blocks for engines to aluminum construction. It tends to be not quite as durable as iron, but its lighter weight means a big boost in performance.

2: Rubber

Tires, in addition to several other car parts, are made from rubber.

What's the one thing all automobiles have in common? They all need tires if they're going to get around. Tires are one of those parts people tend to take for granted, but they're one of the most vital parts of any vehicle. This is where the importance of rubber comes into play in auto manufacturing.

Automotive manufacturing is the driving force of the rubber industry, as about 75 percent of the world's natural rubber production is used to make tires for vehicles [source: Industrial Rubber Goods]. The rubber tire protects the rest of the wheel and its internal parts from wearing down, which can be good for fuel mileage and road safety.


In addition to the all-important tires, parts such as wiper blades, engine mounts, seals, hoses and belts are also made from rubber. As with plastic, it's a very durable, cheap and flexible material that has a wide array of uses in automobiles.

1: Glass

Glass is used for windshields to protect passengers from the elements and potential flying objects.
© Britten

What good is a car if you can't see out of it? As with rubber, glass is one of the unsung heroes of automotive manufacturing. It's also heavily linked to the auto industry -- when business drops greatly for automakers, glass manufacturers also experience job losses [source: Glass Magazine].

Glass is used in many areas of your car. Obviously, its primary use is to create windshields so you can see properly while remaining safe from any airborne objects. It's also used to create rear and side-view mirrors to boost your view of what's around you while driving. In addition, its cousin fiberglass is also commonly used in auto manufacturing as an insulation material on cars.


However, as technology advances, glass is also being used to create more innovative parts on cars. For example, it can be used to create navigation screens and lenses for back-up cameras to allow drivers to have an even better view of what's behind them.

For more information about automobile manufacturing and the materials involved, see the links on the next page.

Car Materials FAQ

What are car bodies made of?
Steel and aluminum are two of the most commonly used materials in the manufacturing of cars, mainly because both are strong metals.
What is the outer part of a car called?
The outer part of a car – not including the wheels or the hood – is called the body. It is the steel frame otherwise known as the chassis.
Are cars made of fiberglass?
Yes. More and more car manufacturers are now using fiberglass in the design of their cars. Fiberglass is mainly used to construct the body of the car because it is lightweight and sturdy.
Why are cars not made of stainless steel?
Stainless steel is not used for manufacturing cars simply because it is more difficult to weld and work with compared to other materials. It’s also very expensive in comparison.
Are cars still made of steel?
Yes, they are. Many car manufacturers still use steel to build cars because of the material’s natural strength and durability. However, there are different types of steel that are used in the manufacturing process.

Lots More Information

Related HowStuffWorks Articles

  • Aluminum Association. "Automotive Aluminum Use Reaches All-Time High In 2009." March 19, 2009.
  • American Chemistry Council. "Plastics Help "Drive" Fuel Efficiency and Safety in New Automobiles at the Los Angeles Auto Show." Dec. 3, 2009.
  • Fountain, Henry. "Many Faces, and Phases, of Steel in Cars." New York Times, Sept. 14, 2009.
  • Glass Magazine. "Downturn in global car industry to blame for glass job losses." Jan. 22, 2009.
  • Industrial Rubber Goods. "Rubber Tires."
  • Sherefkin, Robert. "Surging steel prices galvanize auto industry." Financial Week, June 9, 2008.