Redefining Car Suspension Systems for Carbon Neutrality

Sustainability and carbon neutrality are a major goal for the automotive industry, and companies are trying hard to improve their sustainability scores. This is an important aspect that is driving the evolution, not revolution in the suspension design segment. In this interview, Dr. Thomas Kersten, Executive Manager Chassis & Powertrain at Volkswagen do Brasil, explores what can be done to reduce environmental impact and to come to carbon neutrality, the goals of achieving weight reduction without increasing cost and environmental footprint, as well as how to effectively manage the conflict between agility, stability, comfort, safety, and sustainability.

Q: Can you explain how sustainability is influencing the direction of suspension system development in the automotive industry?

Thomas

The automotive industry faces a huge challenge to transform its business into a more environmentally friendly activity. This also impacts developing markets such as Brazil and South America (SAM), which are regions of more than 20 markets where sustainability demands are being translated into pollutant emission and energy efficiency legislations in an environment of economic, social, and infra-structure difficulties that jeopardises the adoption of European solutions such as Battery Electric Vehicles (BEVs).

On top of that, commitments such as that initiated by Volkswagen Group to reduce CO2 emission of the whole value chain (cradle to grave) to zero until 2050, and to increase the pressure on all product development areas. Suspension systems are no different, with contributing factors, such as:

• A constant search for lower rolling resistance (for instance via tire development)

• Lighter components that must coexist under an extreme market with challenging material cost restrictions

• Safety and comfort customer demands

• The need for space with other vehicle systems such as fuel tank, exhaust system, and hybrid system battery.

Sustainability is therefore the newly added criteria for the already known trade balance in suspension development criteria.

Q: As an Executive Manager at Volkswagen do Brasil, how do you see automakers contributing to the reduction of environmental impact and achieving carbon neutrality through their suspension system designs?

Thomas

I see that not only VW SAM is searching for designs that consider environmental issues, but the competitors in that region have been moving in this direction. The difference is in the importance that each manufacturer gives to the parameters affecting vehicle behaviour. Safety, for instance, plays a key role for VW SAM (which sometimes affects price competitiveness), without any compromise. Additionally, sometimes decarbonisation actions are taken without the necessary attention to the whole life cycle, and their effects are not measured properly.

Q: The automotive industry aims for sustainability and carbon neutrality, but how does this goal specifically drive the evolution (not revolution) in the suspension design segment?

Thomas

First, we must accept that we will not achieve carbon neutrality in the very next project. We need to establish steps for a reasonable roadmap, otherwise, we kill the product competitiveness, delivering market share to companies with less environmental concern. Since the sustainability criteria must play a key role in development, it is primarily crucial to develop this based on very well-discussed targets, involving not only the OEM, but also suppliers and not just technical departments, but also marketing research teams and life cycle assessment and environmental professionals.

Since the number of variables has increased, smart development solutions that include digital simulation and other simulation tools play a key role. Therefore, the essential ingredient for the evolution is the knowledge of the engineers, obtained through excellent academic formation and via well-managed multidisciplinary teamwork, necessary to deal with the harmonisation of suspension development criteria (durability, comfort, safety, weight, pollution, etc) in the changing environment.

Q: How can automakers effectively achieve weight reduction targets without increasing costs and the environmental footprint?

Thomas

The weight reduction target is a good example of a new development criteria. It can directly reduce energy consumption and CO2 during the vehicle use phase; but depending on how this reduction is achieved, there could be less reduction than expected (or even an increase) due to the higher effects during manufacturing and end-of-life phases. Maybe the change of material is not the best choice to comply with the decarbonisation target when the whole life of the vehicle is taken into consideration. With a weight reduction via part design (topology), optimisation can be the best option depending on the defined targets. Again, here the knowledge and the partnerships to increase it are very necessary to realise and assess all possible vehicle use cases, material and process variation, etc.

Q: The suspension system must strike a balance between agility, stability, comfort, safety, and sustainability. How can automakers effectively manage this conflict and address these different requirements simultaneously?

Thomas

This development conflict is not new for chassis development, if you take the classic conflict between comfort and agility, for instance. As mentioned above, this must be managed by careful development target definition. These targets had normally defined the vehicle handling characteristics. The number of criteria increases, including the sustainability issues (such as CO2, pollutant/particulate, and recyclability) and the complexity of analysis. Also, it should be considered that the weight given for different characteristics is also changing. Agility, for instance, may lose importance for safety, comfort, and sustainability criteria, as autonomous driving evolves. Only via a robust set of simulation tools, it will be possible to consider all the issues without an explosion of tests/prototypes and development costs. Again, the knowledge and the partnerships play a key role.

Q: What are some innovative approaches or technologies that automakers can implement in suspension systems to improve sustainability and reduce the environmental impact?

Thomas

The competencies on sustainability issues must be developed and added to chassis teams directly or via teamwork. Also, for sustainability-focused solutions, simulation tools play a decisive role and should be developed with this as a priority. Innovative technologies involving materials, design, or manufacturing processes require research, reinforcing the necessity of partnerships to deal with complexity and cost.

Another approach is the development specifically for the region due to market characteristics. A good example is the use of ethanol (a well-established Otto fuel in Brazil) as a measure for fast mobility decarbonisation. Since it has a low energy density, the tank volume and the combination with electrification technologies to increase range are important for the customer, bringing chassis

design challenges that may not exist in other markets. Also, the development of tires must combine the low rolling resistance with (sometimes very) bad road conditions, which in turn makes the customer prefer higher suspensions, creating a conflict for aerodynamics, CO2, and stability.

Q: Sustainability goals often involve long-term planning. How does Volkswagen do Brasil approach incorporating sustainability considerations into its suspension system development strategies for future vehicles?

Thomas

The VWB approach is to create competence in sustainability issues and add this to the vehicle development process via teamwork. An example is our new department called Way to Zero Center, created in November 2022, side by side with the chassis and powertrain development. The new group should push for sustainability-related competencies and support the integration of these new requirements into vehicle development. It will take time, but we took the first step in the direction of having the “Design for CO2” approach and key performance indexes (such as a Decarbonization Index for the region) to measure our evolution.

Q: As an expert in the field, what do you think are the key challenges that the automotive industry will face in achieving carbon neutrality, particularly concerning suspension system development, in the next decade? And what steps can be taken to address these challenges?

Thomas

The challenges will be the equilibrium between the pillars (agility, comfort, safety, environmental conflicts, costs, and so on), especially when we consider the physical limits. For instance, we most likely will never achieve a zero rolling resistance tire, but company engineers must be aware of research to understand how low this parameter can go in the next project.

I would comment on three main actions or steps: to have a road map of concrete targets to be achieved and from this to derivate technology roadmaps. Since this is done for the long term, adaptions and corrections (according to new knowledge and experiences acquired) should be done periodically; the company should also support the government to develop a reasonable regulatory framework that does not put privilege on single technologies but on the desired effect (low CO2 for instance); and finally to give the customer a strong voice into the company, being necessary to establish the competence to identify in advance what brings (or will bring) value for the customer.