Automotive lightweighting; a powerful ally in the fight against climate change
The approach is to combine not only materials but multiple functionalities in a single component, to reduce the total number of components, hence reducing weight. This would mean that in the future a car’s dashboard could serve as a screen and a haptic interface, or a roof as a battery!
In this Bax & Company insight, Marcos Ierides and Johanna Reiland break down automotive lightweighting in Europe and its crucial role in meeting our decarbonisation targets.
Transport is one of the most important building blocks for our society and its growth. This is particularly true for road transport, which is an essential pillar of European employment, trade and economic productivity, and development.
Our increasing reliance on transportation of goods and people is evident in the emissions attributed to transport activities. In 2017, the transport sector was responsible for 25% of total GHG emissions in Europe, while road transport was responsible for 72% of that, some 0.8Gt CO²eq. For comparison, our remaining carbon emissions “allowance” until 2050 is 350Gt. If we stick to this allowance, we’ll have a 67% chance of avoiding irreversible environmental impact.
Aiming to deliver on the decarbonisation targets of the European Union, automotive OEMs and their value chain partners currently follow two distinct approaches:
Both benefit from the reduction of vehicle weight, which ultimately increases the distance travelled per unit of fuel/energy. In fact, efforts to reduce the weight of cars go way back, with the first significant weight reductions achieved shortly after the 1973 oil crisis. Although research and development of new lightweight technologies have resulted in materials with higher lightweighting potential – lower weight while achieving the same mechanical performance – the weight of cars has actually been increasing since 1980, mainly due to additional comfort and entertainment features, as well as safety systems.
The main drivers for lightweighting are increasingly stricter regulations on emissions, fuel consumption and efficiency around the globe. In Europe, these are expressed by the National Emission Ceilings Directive, which is a part of a larger regulatory push to achieve a climate-neutral Europe by 2050. In the US and China, they are expressed by the CAFE and CAFC standards respectively, which define fuel economy and fuel consumption ceilings.
Next to the regulatory push, lightweighting is highly influenced by other external forces. As new technological, societal and political developments are in motion, the automotive market is in the midst of a historic change.
Shared mobility will have an influence on car production volumes and business models. Several carmakers are already exploring ways to become fleet operators, e.g. Daimler’s Car2Go or Volkswagen’s WeShare car-sharing services. These developments will, in turn, influence the choice of lightweight technologies, as higher production volumes could make costly materials with higher lightweight potential viable, while changing the ownership to a fleet operator will create an even higher incentive for a fuel/energy economy.
Alternative powertrains and, in particular, electromobility, is becoming the prevalent solution for the reduction of transport-related emissions. Lightweight materials are an important enabler for increasing the range of electric vehicles (EVs). Additionally, new vehicle architectures dictated by EVs (e.g. eliminating the need for a gearbox) could favour the use of certain materials which previously were not viable due to complex component geometries.
Autonomous driving is expected to significantly increase the number of components needed for connectivity. This increase in components will translate to additional weight, which could be as high as 200kg per vehicle¹. In order to compensate for this increase, lightweight materials will be necessary.
Until now, lightweighting efforts focused, with few exceptions, on improving the performance of a single material; going from high-strength steel to ultra-high-strength steel. Now the focus is gradually shifting to a multi-material approach, gaining a better understanding of how multiple materials can be combined in a single component to take advantage of each material’s strength. The next step in this approach is to combine not only materials but multiple functionalities in a single component, to reduce the total number of components, hence reducing weight. This would mean that in the future a car’s dashboard could serve as a screen and a haptic interface, or a roof as a battery!
Furthermore, in the past, lightweighting has been driven by reducing use-phase emissions. This is now shifting towards decreasing the environmental impact throughout the whole material’s lifecycle, from extraction and processing, to use, and to recycling and post-processing of secondary materials.
Overcoming these challenges requires the close cooperation of multiple stakeholders with multidisciplinary backgrounds aiming to innovate lightweighting from different angles; technology, policy, the market and the entire ecosystem.
If you want to know more about our perspective, and our collaborators’ perspective on lightweighting, take a look at our publications: