Two international studies confirm the benefits of the light metal

Two studies that relate to the beneficial use of aluminium in the automotive industry for cars, trucks and trailers, were recently published. The studies were based on the same premises: The use of aluminium results in a lower vehicle weight with a corresponding decrease in fuel con-sumption and CO2 emissions.

Greater weight reduction potential than steel
Using aluminium in key automotive components can safely reduce vehicle weight by as much as 40%, compared to only 11% for high-strength steel, according to a study conducted by the University of Aachen. The report, conducted by the Institut für Kraftfahrzeuge at the University of Aachen for the European Aluminium Association, analyzed 26 automotive components to assess the further potential or limits of weight reduction for both steel and aluminium.
«Aluminium use in the automotive sector has increased steadily for the past four decades; how-ever this new study makes clear the environmental and safety advantages of the high-strength, low-weight material have yet to be fully realized. This study combined with other data on the benefits of aluminium suggest a total of about 238 kilos of additional weight savings, which could result a nearly 10% further improvement in fuel economy over a typical auto today. This can be done while maintaining - if not further improving – vehicle safety» said Randall Scheps, Chairman of the Aluminium Association’s Aluminium Transportation Group and Alcoa’s Director of Ground Transportation.
The study found that using aluminium could result in significant weights savings for the analyzed components, ranging from 14 to 49%. Using a state-of-the art steel reference car, the maxi-mum weight reduction potential of aluminium in car bodies is approximately 40%.
«Aluminium is more crash absorbent than steel and can safely cut vehicle weight without reducing vehicle size. This offers great potential, since lighter vehicles can produce fewer emissions and need less fuel or battery power to operate» Scheps said.
Weight reduction potential using high strength steel was limited to only an additional 11%. The reason the potential weight reduction using high strength steel is so small, is that nearly 40% of the parts analyzed simply cannot be made thinner regardless of the grade of steel used.
Potential for automotive aluminium lightweighting varies and options include maintaining a steel body with aluminium closures, hang-on and mounting parts, hybrid or multi-material designs for the body and full aluminium body.
«The study confirms that the lightweighting potential is still considerable. Debates in Europe usually focus on improving powertrain technologies to improve the well-to-wheel energy con-version efficiency, but this only addresses the ‘supply’ side of the story and ideally should be complemented by vehicle mass reduction, in order to reduce the ‘demand’ for energy at the wheel» added Bernard Gilmont, Transportation & Building Director for the European Aluminium Association. Scheps concluded that «lightweighting the world’s overall transportation fleet through the use of aluminium has the potential to reduce greenhouse gas emissions by nearly 660 million tons annually, or 9% of global, transportation-related greenhouse gas emissions».

Fuel and payload savings improve in trucks and trailers
Substituting high strength, low weight aluminium for more traditional materials in Class 8 truck and trailers can eliminate 1500 kilos from the vehicle weight, according to a new report released by Ricardo Inc. The study was commissioned by the Aluminum Association Inc.’s Aluminum Transportation Group to analyze the fuel efficiency impact of lightweighting Class 8 trucks and trailers. The study simulated different configurations of vehicles and payload conditions (i.e. unloaded, gross vehicle weight [GVW] and half-GVW load) for the major drive cycles that represent commercial transportation in the United States. Based on these findings, aluminium could yield annual savings of fuel and emissions in Class 8 trucks and trailers as high as 6,000 litres and 17.9 tons of CO2. When considering these results for the total United States fleet, approximately two million vehicles, the overall economic and environmental impact of weight savings may be 4 billion litres of diesel and 10 million tons of CO2 per year. Driven largely by payload considerations, aluminium has experienced more than 30 years of continual growth in commercial applications. Today, the average Class 8 vehicle uses over 450 kilos of aluminium; however, this new study confirms that by further reducing overall vehicle weight with aluminium, transporters can load their vehicles with an additional 6.5% of payload at gross vehicle weight (GVW). This equates to fewer trips and an “effective” fuel and emissions savings of 6.5% for equivalent average ton-mile freight efficiency.