Carbon fiber is not a cheap material. If it was, we'd all be driving around in cars made from it--rather than it being limited to a few supercars and high-end sports cars.

And the BMW i3, of course. The expense of its carbon fiber-reinforced plastic (CFRP) chassis might lead you to assume repairing it would be a wallet-draining nightmare--but apparently, that isn't the case.

As Autoblog Green reports, BMW's clever construction methods mean minor and even major repairs may be cheaper than that of a standard steel vehicle.

And because repairs are cheaper, insurance rates should be cheaper too--a car that doesn't cost much to repair means less risk for your insurer if you have a bump.

This ease of repair and lower cost of construction is important for BMW, which says that everything BMW has learned from the i3 will eventually find its way onto the maker's regular vehicles. "There is a plan to bring CFRP to the rest of our fleet," communications manager Manuel Sattig told Autoblog Green.

As you'd imagine, expanding the material to the rest of the range means repair costs can't simply spiral out of control on every CFRP vehicle.

That's where the clever engineering starts.

The i3's exterior panels are mostly plastic. They're also attached by a simple system, allowing them to be swapped for another panel with very little work. It's the same reason cars these days have plastic bumpers and some cars even feature plastic front fenders.

Not everyone is lucky enough to get away with just a small accident, though. Larger ones will likely damage the CFRP itself, which is where another useful feature comes in.

Instead of deforming, like steel or aluminum, CFRP simply breaks. In doing so it absorbs energy just as metal would, but that energy isn't transferred to other parts of the chassis. Damaged CFRP components--there are 30-35 on the car--can be cut out and new ones bonded in. It's a quicker process, and this reduction in labor time contributes to the lower cost.

As a result, both the NHTSA and its counterparts in Europe have granted the i3 a low insurance rating--happy that even large repairs will cost much less than you'd imagine.

Carbon fiber itself isn't cheap. But if used well, there appears to be little reason it can't be cheaper to repair than the car sitting on your driveway.


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