Sustainability assessment for different design solutions within the automotive field

Sustainability is a critical issue for the automotive industry, making that car manufacturers have to address also environmental issues additionally to the traditional ones. Within this context, many research and industry activities have been concentrated in the field of lightweighting through the development of innovative materials and manufacturing technologies. This study deals with the sustainability assessment of two alternative design solutions for a door demonstrator module: a reference steel-based door structure is compared to a re-engineered variant which is mainly constituted of state-of-the art aluminum. Environmental impact, energy consumption and cost are chosen as sustainability pillars and the results are expressed respectively in terms of Global Warming Potential (kg CO2 eq), Primary Energy Demand (MJ) and total cost (Euro). The analysis follows a cradle-to-gate approach, capturing the contributions due to raw materials extraction, component manufacturing and operation; the use stage is evaluated for both Internal Combustion Engine Vehicle (ICEV) and Electric Vehicle (EV) variants. The inventory for energy and impact assessment is mainly based on primary data directly measured on process site. The overall profile of the different design solutions is assessed and the main, environmental, energy and cost life-cycle hotspots are identified and critically discussed. The dependence of indicators on life-cycle mileage is investigated for both ICEV and EV case studies by means of the break-even point analysis. Finally, the effective convenience of reference and lightweight alternatives is evaluated considering the overall set of sustainability aspects through a multi-criteria decision analysis.