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by kart23 702 days ago
Why aren't more regular cars made of carbon fiber? Especially with EVs needing to be as efficient as possible.

The BMW i3 had a carbon fiber frame and was still reasonably priced back in 2013, yet no other normal cars seem to have went this way.
4 comments
daviddumenil 702 days ago
In the case of the BMW i3, European legislation was introduced that made manufacturers accountable for the recyclability of their cars.

Something the article completely sidesteps when talking about metals versus composites :-)

Cost versus steel may well have been a factor as well.

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fkarg 702 days ago
from what I understand it's because it's a lot more expensive than its alternatives.

Like yes, for a bunch of structures you can neatly automate it (see most rocket production), but the shapes of (current) cars don't easily offer themselves to similar options. Automation is possible but would probably be finicky and require a lot of space and energy (for the heating).

but someone else please jump in if you know better/more.

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floxy 702 days ago
Here's to hoping that Aptera becomes a regular car someday.

https://aptera.us/cpc-group-agreement/

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tpm 702 days ago
Because it doesn't make a lot of sense to invest heavily into saving 100kg on the frame and then adding a 500kg battery. The i3 had a small, lighter battery and an extender.
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janalsncm 702 days ago
If your frame is 100kg lighter doesn’t that mean you can get even better mileage out of your battery? Or, for the same weight, fit even more battery?
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theluketaylor 702 days ago
The range killer is really drag, not weight. Weight contributes, but at high speed drag is such a large draw that nearly nothing else matters.

The rolling resistance coefficent of a car tire is about 0.01 and the force grows linearly with mass. Drag is v^2 and the coefficients are more like 0.2 - 0.3 of the frontal area on most EVs.

Weight savings don't offer that much range savings so there isn't much incentive to pull weight out of a design, especially when carbon fibre tub construction is so much more expensive.

BMW made a bet batteries would remain very scarce and expensive, a bet they lost pretty throughly.

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tpm 702 days ago
Yes, but is it cost-effective? Will the customer buy it?
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