What Materials Are Cars Usually Made Of?

Various materials go into your car during the manufacturing process. Each material possesses unique properties that make it suitable for a part or component. For example, glass is see-through, making it desirable for windshields and car window glass panes.

So, why is it important to know what are cars made out of? Knowing what material went into a part can prove helpful while maintaining and repairing your car. You can pick a replacement part made of the same material with the assurance that it will deliver roughly the same performance as the older one. Or you can choose a product made of a superior material for improved capabilities and durability.

What Are Cars Made Of?

Here are the most commonly used materials that your car is made of: 

Steel

Steel is one of the heaviest and most widely used materials used in car manufacturing. It comprises a significant percentage of a car’s mass. The World Steel Association reports that the typical 2019 model used an average of 1,800 pounds (900 kilograms) of steel. Since the average 2022 model weighs slightly more than 4,000 lbs, steel makes up a significant percentage of its mass.

One of the critical parts is the chassis, the frame that supports the weight of the engine and passenger body. During a collision, the chassis protects you and your passengers from injury by holding the rest of the vehicle together. What are car frames made of? Steel gives the chassis the structural strength required to bear heavy weights without bending or breaking.

Other steel parts and components include body panels, door beams, and roofs. Many engine and exhaust parts are also made of steel, especially when weight isn’t a concern. Exhaust manifolds, tailpipes, and other parts of the exhaust system use stainless steel that can handle high temperatures and exposure to corrosion.

Steel has come a long way since the first all-steel-body vehicle in 1916. Manufacturers have developed different types of steel to meet various requirements. For example, some parts require steel that can crumple to dampen the impact of a car crash. Meanwhile, other parts use steel that rigidly holds its shape under pressure.

Plastic

Plastic is the most common material used in car manufacturing. It makes up roughly 50% of the volume of a typical model in recent years. Tough, cost-effective, and capable of being molded into almost any shape and form, plastics are everywhere in your car. Plastic is also lighter than metal, which helps reduce overall vehicle weight for better fuel economy.

Car and engine parts made of plastic include the following:

• Air bags
• Air conditioner vents
• Dials and instrument cluster housings
• Dashboard and console parts
• Door handles and door panels
• Floor mats
• Seat belts and other seat parts
• Switches and power window regulator parts
• Intake manifolds and snow shields
• Rocker arm (valve) covers
• Power steering pump pulleys
• Emission control components (solenoid valves, etc.)
• Radiator tanks
• Coolant surge tanks
• Coolant hose outlets and hose tee fittings
• Wheel center caps
• Headlamp and taillamp assemblies
• Grilles
• Fender splash shields
• Wire harness connector shells
• A/C plenum chamber and air doors (under dash)
• Fuse panel/junction boxes

As you see in the list above, many engine parts and components are plastic. You only need to look at the brightly colored plastic handle of the oil stick, which keeps your hand clean and insulates your fingers from the heat of the oil.

Some car manufacturers are finding ways to use plastics in the car body and even the engine. Switching from steel to plastics can shave precious weight off the car, and some plastic types can match metals in specific performance ranges. For example, plastic fuel tanks weigh less than their steel counterparts while doing a great job of storing diesel or gasoline.

Aluminum

Aluminum is a malleable, lightweight metal. It’s an attractive alternative to iron and steel in many applications that require durability and weight savings.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Pistons in engines have been aluminum for as long as there have been internal combustion engines. Some connecting rods are aluminum.

Aluminum has been growing more important in car manufacturing. In 1970, the element made up only 2% of the mass of a typical car. In 1990, the percentage increased to 5%. By 2009, roughly 9% of the average car’s weight was aluminum.

Wheels are often made of aluminum. So are many engine blocks, suspension components like control arms, and brake parts such brake calipers and master cylinders. The center part of the radiator is aluminum, as are many heater cores. Transmission housings (both manual and automatic) have been made of aluminum for decades.

The aforementioned parts previously used steel or iron. Removing and replacing such heavy parts proved difficult and exhausting. In particular, race car drivers and their support team keenly felt the excess weight whenever they had to pull into a pit stop to replace a wheel or lift the engine block out of the engine bay.

Switching to aluminum engine blocks and wheels saved considerable amounts of weight. They also took less time and energy to remove from the car to make room for their replacement.

Aluminum body panels are another way to save weight. Supercars and other performance cars often use lightweight panels to keep their weight down. The Acura NSX and Audi R8 are two examples of supercars that extensively use aluminum panels.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Aluminum body panels have been used by some vehicle manufacturers for over 100 years. Aluminum hoods started appearing on some vehicles in the 1980 and 1990s, and in 2015, F150 pickup bodies have been all aluminum.

Rubber

Rubber is a durable and elastic material. Most rubber is natural and extracted from plants, but some are petroleum products. Various car parts leverage the flexibility and toughness of rubber for many applications.

The most prominent car parts made of rubber are the tires. Your car or truck can’t move without tires. Good tires use high-quality rubber that can resist drying and keeps the wheel safe from getting worn out.

Car tires make up 75% of the natural rubber production worldwide. But tires aren’t the only car parts made of the material. Drive belts, engine mounts, hoses, seals, and windshield wiper blades also use rubber. The parts often need to bend and stretch without breaking, and rubber performs admirably in these roles.

Glass

Last but not least is glass. Like rubber, glass seems boring at first glance, being see-through to the point of being invisible. But the parts made from glass play crucial roles in your car. While you can drive without a windshield, it’s uncomfortable and dangerous.

Glass is the primary material in vehicle glass, like car door glasses and front and rear windshields. They use laminated or tempered glass, which gives you a clear view while withstanding most impacts.

Rear and side-view mirrors are also made of glass. These mirrors improve your vision and awareness of what’s happening behind and to the sides of your car.

Fiberglass is a type of plastic made from glass fibers. Cars use fiberglass as an insulating material that captures air and slows the movement of heat. Whether it’s cool or warm, fiberglass insulation can help keep the interior at a comfortable temperature.

Car electronics also use glass for various roles. Digital displays and screens use glass as their material. The backup cameras in driver assistance systems use glass lenses to see behind the car.

In addition to these, your car is made of smaller amounts of other materials like copper, lead, and titanium. Together with the more numerous materials like steel and plastic, they ensure that your vehicle meets the manufacturer’s specifications and your personal requirements.