Beyond Strong: Steel is Lightweight

As automakers develop the next generation of vehicles, they’re seeking lightweight material innovations to meet evolving regulatory requirements, such as the Corporate Average Fuel Economy (CAFE) regulations in the United States. The steel industry is meeting this need through the development of new advanced high-strength steel (AHSS) grades, whose unique metallurgical properties and processing methods enable the automotive industry to meet current and future industry fuel, emissions and safety requirements, while keeping cost down.

“Lightweighting” is often cited as an important way to reduce greenhouse gas (GHG) emissions from light duty vehicles. This is misleading as the ultimate goal is not lower weight, but lower emissions. Focusing only on lower weight may lead to the selection of light materials, such as aluminum and magnesium, which are emissions-intensive in their production. Such selection can lead to the unintended consequence of lighter vehicles with higher emissions due to the GHG emitted during materials production.

The correct term and goal is “low-carbon lightweighting,” meaning lightweighting that’s achieved with low-emitting light materials, such as advanced high-strength steels (AHSS). This is described below.

Low-Carbon Lightweighting with AHSS:

  • Employing new grades of AHSS can reduce a vehicle’s structural weight by as much as 39 percent. This is an example of low-carbon lightweighting and doing so with AHSS ensures the lowest emitting vehicles are designed and put on the road.
  • AHSS allows automakers to address society’s need to reduce GHG emissions without compromising safety, performance or affordability.
  • Producing steel has the lowest emissions of the major automotive materials. The higher GHG emissions from producing competing automotive materials are significant.
  • Very little aluminum automotive sheet is currently in use or available for recycling. This means that any increased use of aluminum sheet for automobiles must come from GHG-intensive primary aluminum production.