Sustainable alternatives series: Lighter design for less energy?

Fuel and energy prizes are on the rise, therefore a sustainable mobility strategy is a must for most, and on top wastefulness in general is just not a very good look anymore. There’s a lot to say in favour of resource-saving cars and even more about methods to create them. In today’s episode of the sustainable alternatives series we talk about manufacturer’s ways of reducing a car’s weight and the conscious design choices of tomorrow.

Driving less and more efficiently and choosing frugal models certainly help to reduce a car’s/fleet’s overall consumption. The biggest saving potential lies elsewhere, however: in the construction choices. Lightweight constructions and alternative materials are part of a field that’s gaining traction by the minute. So what is this all about? The lighter the car and smaller the engine/battery, the less energy is needed to move. Seems intuitive enough. While this is true to a certain extent, the impact on the actual energy balance is not without controversy. A heavier car can also regain more energy through recuperation, after all. One of the main goals of reducing weight in a car is therefore also to save valuable resources and positively influence its environmental impact and footprint.

This is most often achieved through a combination of these measures:

1)    Getting rid of the unnecessary

If you want to travel lightly, you pack less. Reducing a car’s components, of course, is not quite as easy. After all, every engineer strives to design as efficiently as possible from the get go. Plus, in order to significantly reduce energy consumption, the car would have to lose hundreds of kilos first while still meeting safety, stability and convenience goals. A very hard task and thus not really a stand-alone solution. Still: every gram counts. Areas in which this method is used can include, for example, the interior, tyres, certain electronical components and more.

2)    Choosing new materials

A modern material suitable for the automotive industry must stand up to comparison with traditional materials such as steel while also bringing desired properties to the table, e.g. being comparatively low in weight, cost, and preferably sustainably sourced. Magnesium, carbon and aluminium are often used low density alternatives, yet thermoplastic and thermoset materials are robust possibilities, as well.

An extensive selection of glass-, metal- or, ceramic-filled polymers as well as liquid silicone rubber (LSR) can also be used to replace metal parts, thus reducing product cost and weight while improving durability. What’s more: Components made of fibre composites achieve a service life of 25 years or over one million kilometres. Conventional car bodies are designed for 200,000 kilometres meaning future cars could be designed to be at least repurposed or even passed down through generations one day.

That does not mean, though, that the “old” materials have to go completely. With its ambitious plans for transforming production, the BMW Group focuses on the principles of circular economy and aims to use more and more secondary materials, such as secondary aluminium and steel. The provision of these saved materials is significantly less environmentally damaging and CO2-intensive than the extraction and production of primary ones.

Beyond that, the Group also looks into materials that seem unlikely at first glance, such as recycled household waste, wood or plant fibres. The bio-based and petroleum-free Mirum™ and innovative Deserttex™ made of powdered cactus and a bio-based polyurethane matrix are examples of the new paths that are being taken. They can be used as vegan and sustainable leather and fabric alternatives that can significantly reduce CO2 while also avoiding animal materials more and more.  

3)    Leave room for ideas

And finally, another great way to save resources is to challenge the existing shapes of the strictly necessary components. Does the axis have to be this wide? Can the frame loose a centimetre here and there? With the help of new, sometimes stronger materials there are new options to achieve the same stability with less. It’s a question of re-evaluating the status quo and cutting down where possible.

We hope you got a good first idea of the topic and that we’ve peaked your interest. If you would like to know more about innovative new models and saving strategies, we’re happy to show you the options. Coming up next in our Sustainable Alternatives Series is our take on eco-friendly interiors featuring car part technology leader Faurecia. So, stay tuned!