PITTSBURGH, PA - The use of advanced high-strength steel (AHSS) for large-scale automotive fleet lightweighting results in an immediate and sustained decrease in greenhouse gas (GHG) emissions associated with production and use of the affected vehicle fleet, whereas the use of aluminum for lightweighting the same fleet results in an increase in overall GHG emissions lasting for several decades according to a study (report and executive summary here) released today by the Steel Market Development Institute (SMDI). SMDI is a business unit of the American Iron and Steel Institute.

 

The study compares a wide range of lightweighting scenarios and, in each case, the use of aluminum would increase overall GHG emissions for many years—offsetting any fleetwide life cycle benefits during the same time period.

 

Dr. Jody Hall, vice president, automotive market, at SMDI, said, “The study demonstrates that lightweighting vehicle body and closure panels with AHSS immediately decreases overall GHG emissions in the production of the steel for the car and the emissions generated during driving. This study differs from some previous studies in that it takes into account the timing of the GHG emissions, which is a critical consideration in the full life cycle performance of vehicles.”

 

Based on study findings, Mark Thimons, vice president, sustainability, for SMDI, noted, “When compared to lightweighting with aluminum, lightweighting an equivalent fleet with AHSS instead results in cumulative net savings of more than 300 million metric tons of GHG emissions by 2038--the equivalent of the emissions resulting from combustion of 45 billion gallons of gasoline. By 2053, an additional 100 million metric tons would be saved--totaling more than 400 million metric tons of GHG emissions savings.”

 

The study incorporated the full life cycle consequences of material selection decisions, including changes in steel and aluminum production, volume of scrap produced and recycled, and use-phase emissions. It augments a 2017 peer-reviewed study from the Steel Recycling Institute (SRI), “Life Cycle Greenhouse Gas and Energy Study of Automotive Lightweighting.”