The world aluminium industry reported earlier this year that the application of aluminiumin in the automotive industry in passenger cars, manufactured in 2006, would lead to potential global savings of approximately 140-million tons of carbon dioxide-(CO2) equivalent greenhouse-gas (GHG) emissions and to energy savings equivalent to about 60-billion litres of crude oil over the life cycle of these vehicles.

“The GHG reductions and fuel savings are the result of weight reduction achieved through the application of aluminium by the world’s automakers,” stated International Aluminium Institute (IAI) secretary-general Robert Chase.

These energy savings and emissions reduction numbers were included in a presentation by IAI research associate Marlen Bertram, at the 2007 China Aluminium and Transportation conference in Dalian, China, entitled ‘Improving Sustainability in the Transport Sector Through Weight Reduction and the Application of Aluminium’.

As part of the presentation, Bertram reviewed the results of a study by the Institute for Energy and Environmental Research (IFEU) in Heidel-berg, Germany, that concluded that reducing the weight of the world’s transportation fleet, passenger cars, trucks, rail vehicles, air and sea craft, has the potential to reduce GHG emissions by 660-million tons a year, or close to 9% of global, transportation-related GHG emissions.

Bertram presented several case studies demon-strating aluminium’s capacity to reduce weight in real-world vehicle applications.

“Our results are based on data from the IFEU study and a life cycle model developed by the aluminium industry. This model accounts for all greenhouse gases emitted during aluminium production, vehicle use and end-of-life processing. It has also been tailored for component-specific applications on passenger vehicles.”

She added that all analyses were based on publicly available information concerning weight reduction achieved through the application of aluminium. “Our model adheres to the principles of life cycle assessment through the International Standards Organisation standard 14044.”

The study also compared aluminium to high-strength steels in two applications: a bumper beam on two similar European-made cars, one using high strength steel, the other aluminium, and a bonnet on a US-made family sedan. In both applications, aluminium achieved significant energy and emissions savings.

The aluminium bumper beam saved 2,6 kg over the high-strength steel beam. Over a 200 000-km driving cycle of these compact vehicles, the aluminium bumper beam will reduce GHG emissions by 15 kg a kilogram of aluminium, or 48 kg for the bumper.

The aluminium bonnet on the US-manu-factured family sedan registered a 42% direct weight reduction over high-strength steel. Over the 200 000-km driving cycle of this vehicle, this hood will reduce CO2-equivalent emissions by 131 kg.

The introduction of a single aluminium bumper beam or a bonnet offers little or no potential for indirect, or secondary, weight savings, whereas a combination of replacements or an all-aluminium body structure enables secondary weight savings of the order of 50% or more. For instance, when the secondary weight savings of the bumper and bonnet are included in the model, the CO2-equiv-alent emissions reductions increase to 61 kg and 161 kg, respectively.

The aluminium industry’s study also revealed that each ton of the light metal replacing iron in engine blocks has the potential to save the energy equivalent of 8 000 8467 of crude oil over its life cycle. According to a 2006 study by Ducker Worldwide, 45 kg of aluminium was put into each car and light truck in the form of engine blocks in 2006, resulting in the energy savings equivalent to 375 8467 of crude oil a vehicle for this applica- tion alone.

“These data underpin the key role that alumi- nium can play in reducing GHG emissions from transport. They also further the 15 objectives of the industry’s global sustainability programme, ‘Aluminium for Future Generations’,” Chase concluded.

The full report also addresses the issue of vehicle size and weight as important elements of sustainable transportation. It presents the results of a previous study done by the Dynamic Research Institute, where size and weight were key variables in 500 ‘virtual’ collisions.

The study concluded that both vehicle weight and size were key elements in producing passenger vehicles that reduce crash energy to save lives. The study demonstrated that maintaining vehicle size while reducing its weight reduces the energy it has to absorb in a crash and making it less damaging to other vehicles in a collision.

The study also shows that if lightweight structural materials, such as aluminium, are used to increase a vehicle’s crush zones, even by several centimetres, significant improvements in safety can be achieved without increasing vehicle weight.