As discussion swirls around how auto makers are going to meet tough federal fuel-efficiency goals by 2025, new evidence points to venerable material, steel, as one of the more promising solutions.
Increasingly efficient engines and electric powertrains will do much to get cars to the pending 54.5 mpg (4.3 L/100 km) corporate average fuel economy standards. But they certainly can’t do it all. Steel, as new evidence shows, has the proven potential to bridge the gap.
Technologically advanced steel products – those available today and those in development – hold the key to making the lighter, more fuel-efficient vehicles of tomorrow. In fact, new data show advanced high-strength steels (AHSS) and ultra high-strength steels can not only reduce mass, but can do so at a lower cost and with less environmental impact than alternative solutions.
This may be surprising news to those who presumed lighter-weight cars of the future would be made of aluminum, magnesium or carbon fiber. While these alternatives share steel’s potential to achieve needed vehicle weight reduction, they simply don’t deliver the whole package.
The steel products available today and under development for the future, will make cars that are safer, lighter and more fuel efficient, while maintaining affordability for America’s new car buyers.
According to the CAFE Compliance and Effects Model, commonly referred to as the Volpe Model that the U.S. Environmental Protection Agency and National Highway Traffic Safety Admin. developed to set their 2012-2025 standards, the weight reduction offered by AHSS provides one of the largest improvements in fuel economy, and the single largest improvement in efficiency per dollar spent than any other fuel-economy improvement technology.
AHSS can provide a 7.2% mileage gain at little or no additional cost to the auto maker, which is up to six times more cost-effective than aluminum.
Cars and trucks made from these advanced steel grades also can be produced using auto makers’ existing infrastructure with little need for additional investments in retooling auto production facilities. Many alternative materials require new equipment and a greater investment of time and money for production. This fact only adds to the conclusion that steel offers the most cost-effective solution for achieving the 2025 standards.
But that’s not the end of the story. In 2025, with a 54.5-mpg fleet average, a steel car will offer a smaller carbon footprint than a car made of an alternative material, such as aluminum or carbon fiber, thanks to steel production being less energy intensive than other materials.
The production of 1 ton of aluminum, for example, requires five times the energy required to make 1 ton of steel. Because the body structure accounts for about one-third of the curb weight of a typical vehicle, an aluminum car requires twice the amount of carbon dioxide to manufacture than a car made of steel.
And steel is easily recyclable. About 30% of the world’s annual steel production comes from recycled scrap.
When the new CAFE standards first were announced, proponents of materials such as aluminum, carbon fiber and magnesium proclaimed it was “game over” for steel. But a close look at the facts and new data show that depiction couldn’t be further from the truth.
With aggressive new fuel-efficiency targets on the horizon, steel’s venerable role as the foundation of the automobile is on track to be every bit as relevant and essential in 2025 as it is today.
Mike Rippey is President and CEO of ArcelorMittal USA, part of the world’s largest steel and mining company and the No.1 worldwide supplier for automotive steels.
