What Materials are Used to Lightweight Cars?

Car manufacturers are constantly pushing to create the lightest cars possible to increase speed and power. So, what materials are most common when an automotive designer needs to cut weight?

The goal in lightweighting a car is to increase performance and efficiency while maintaining safety and comfort. Roughly speaking, when a car’s weight is decreased by 10%, the efficiency of the vehicle can increase anywhere from 5 to 8 percent. This may not seem like a lot, but in the competitive automotive industry, it can make a world of difference.

Modern cars are mostly steel and steel is heavy. Back a few years ago, the average car contained 2,400 pounds of steel and the average SUV contained 3,000 pounds of steel. That’s just for the metal. When you add in everything else needed inside of modern cars, the gross vehicle weights can often skyrocket.

Compared to standard steel construction, here are the most common materials used to lightweight cars

• Magnesium
• Carbon Fiber
• Aluminum/ Al Composites
• Titanium
• Glass Fiber
• High Strength Steel

There are tradeoffs when it comes to each of these materials, whether that be cost or comfort. Carbon fiber is usually only used in cars with hefty price tags, yet it is one of the most effective ways to maintain or increase strength while decreasing cost. Each material also presents its own manufacturing problems. Titanium, for example, is hard to work with due to its impressive strength. Structural Glass fiber can become a hazard to workers. When it comes to choosing a material to lightweight a car with, it often comes down to the minute details of a design and the manufacturing capabilities of the company.

While lightweighting is used to increase the efficiency of cars, it may not be for the reasons you may think. Just making a car lighter through blind choice isn’t the answer. Rather, design engineers have to take into account the optimum operational curve of modern engines and match a cars’ weights to it. In some cases, lightweighting may be more about hitting a target weight for a certain engine rather than making the car as light as humanly possible.

Lightweighting is also becoming more of a necessity in modern automobiles as hybrid and fully electric systems take off. Batteries are heavy, there’s no way to get around it. If you want to pack your car full of heavy batteries and also get the best range on the market, your car has to be as light as possible. Teslas, for example, are made from aluminum to decrease weight. The undercarriage is manufactured from titanium and high-strength steel is used in critical loading points to increase safety. This plays into the need to lightweight electric vehicles as well as the fact that one material isn’t the cure all to solving lightweighting problems.

Lightweighting is the present, and the future, of the automotive manufacturing industry. It brings innovative materials to the frontline of design. Car manufacturing looks a lot different from how it did 50 years ago, and for the most part, that’s a good thing.

Sources: Technology Review, How Stuff Works, Car Wow

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