Pros & Cons of Advanced Lightweighting Materials

Although cars have been around for more than a century, the material they are made of (steel) has mostly stayed the same. It has only been in the past few decades that advanced materials ranging from aluminum and magnesium alloys, to carbon fiber composites, have made their way into mass-produced passenger cars.

Advanced materials are essential for boosting the fuel economy of modern automobiles while maintaining safety and performance. Because it takes less energy to accelerate a lighter object than a heavier one, lightweight materials offer great potential for increasing vehicle efficiency. A 10% reduction in vehicle weight can result in a 6 to 8 percent fuel economy improvement. Replacing traditional steel components with lightweight materials such as high-strength steel, magnesium (Mg) alloys, aluminum (Al) alloys, carbon fiber, and polymer composites can directly reduce the weight of a vehicle’s body and chassis by up to 50 percent, and therefore reduce a vehicle’s fuel consumption. Using lightweight components and high-efficiency engines enabled by advanced materials in one-quarter of the U.S. fleet could save more than 5 billion gallons of fuel annually by 2030.

By using lightweight structural materials, cars can carry additional advanced emission control systems, safety devices, and integrated electronic systems without increasing the overall weight of the vehicle. While any vehicle can use lightweight materials, they are especially important for hybrid electric, plug-in hybrid electric, and electric vehicles. Using lightweight materials in these vehicles can offset the weight of power systems such as batteries and electric motors, improving the efficiency and increasing their all-electric range. Alternatively, the use of lightweight materials could result in needing a smaller and lower-cost battery while keeping the all-electric range of plug-in vehicles constant.

Scientists already understand the properties of these materials and the associated manufacturing processes. Researchers are working to lower their cost and improve the processes for joining, modeling, and recycling these materials.

The U.S. Department of Energy’s Vehicle Technologies Office (VTO) develops advanced materials that help boost the fuel economy of modern vehicles, while maintaining safety and performance. Further developing advanced materials requires increasing understanding of their composition and morphology. Computational materials science should bring advanced materials into the market much faster than in the past. Researchers can also use computational approaches to create vehicle designs that maximize the potential of these materials. To improve these tools, VTO works with the Lightweight Materials National Laboratory Consortium (LightMAT), a network of 10 national laboratories with technical capabilities highly relevant to lightweight materials development and utilization.

Research and development into lightweight materials is essential for lowering their cost, increasing their ability to be recycled, enabling their integration into vehicles, and maximizing their fuel economy benefits. Although many materials show promise in reducing vehicle weight, there are pros and cons to each, ranging from production costs to property deficiencies.