At the moment, BMW is pushing carbon fiber hard. We already knew that the Bavarians used extensive amounts of carbon fiber in its i Division cars, such as the i3 and i8. Both cars are almost entirely made of the stuff, that’s why they’re so expensive. But open the door of even the new 7 Series and you’ll see a little badge on the B-pillar that says “Carbon Core“, which is of course made from carbon fiber as well. But what this badge indicates is that there are certain components of the chassis that are made from carbon fiber to reduce weight and increase structural rigidity. However, don’t expect this trend to continue to lower-end models any time soon.
Carbon fiber, though far cheaper now than it was even ten years ago, is still incredibly expensive in comparison to steel. The average cost of carbon fiber in a modern BMW is about 16 Euros per kilo, whereas the average cost of common steel is less than a Euro per kilo. That’s a massive price difference and one that simply doesn’t make sense in less expensive cars.
In high-profit margin cars, like the BMW 7 Series, it’s not difficult to add carbon fiber to the chassis while still maintaining healthy profits. However, in smaller-profit margin cars, like the BMW 3 Series, which make money based on volume, it’s next to impossible. Which is why, until BMW can work on developing carbon fiber at a far cheaper cost, we won’t see “Carbon Core” in anything less the 7 Series. Even in the newly released G30 5 Series, whose chassis is based on the more expensive Carbon Core-laden 7 Series, doesn’t have the stuff. Instead of carbon fiber, BMW uses magnesium and aluminum to lower the curb weight, as it’s far cheaper.
According to BMW CEO Harald Krueger, “The material is still too expensive and for smaller segments and smaller vehicles it can be not competitive,”. So don’t expect any fancy lightweight 3 Series any time soon.
One other area carbon fiber does also work is in electric cars. For instance, the BMW i3 is mostly made from carbon and BMW is able to sell it for a relatively competitive price. The reason is that the lighter the car is, the need for big batteries decreases and batteries are the most expensive part of the car. So the lighter the car, the cheaper it ultimately becomes. However, it still isn’t cheap and that’s why the BMW i3 is more expensive than its new competitors like the Chevy Bolt and upcoming Tesla Model 3. And while the i3’s fancy construction was charming and futuristic when it first debuted, its charms are wearing thin, thanks to competitors offering EVs with far more range and a lower cost without having to resort to carbon fiber construction.
But if there is a brand to crack the code on affordable carbon fiber construction, it’s BMW. After having been the first automotive company to develop a (relatively) cost effective means of developing carbon fiber for the i Division, BMW now has a head start on its competitors. Though, BMW is now looking into blending carbon fiber with other materials, such as aluminum, to keep it strong and affordable. We’ve already seen this in the industry, with Pagani’s so-called “Carbotanium”, which is a blended weave of carbon fiber and titanium. However, BMW’s method would be a lot cheaper. But, again, it will take time to figure this out.
“It takes time to learn how it behaves in manufacturing, how it reacts to being bonded to other materials. This has implications for tooling, purchasing and manufacturing. We understand the complete development chain,” said BMW’s Jochen Kopp.
A future where carbon fiber-extensive cars at an affordable price is a bright one. It will allow cars to be lighter, more efficient, faster, stronger and even safer than ever before. Plus, it’s more renewable, can more easily be made from recyclable materials and even more easily be recycled. So developing a more affordable means of carbon fiber for automobile construction is something worth investing in. But it will take quite some time, so don’t expect to see it any time soon.