Thanks to its lightweight construction, the BMW i3 extended-range electric vehicle gets exceptional fuel economy and range.
The same thing that makes the BMW i3 lighter and more efficient also makes it cheaper to own than conventional vehicles or even some other electric vehicles. The key lies in BMW’s use of a new material for the safety cell, that is, the body. Of course, like many modern automobiles, there are many exterior panels and components that are plastic. Bump a headlight, and you can simply bolt a new one in. Damage the rear bumper cover, and the plastic panel simply snaps in, typically using screws or plastic rivets to restore the appearance of the vehicle.
The safety cell of the BMW i3 is unlike pretty much all conventional and electric vehicles on the market today, because it is made of carbon-fiber-reinforced plastic (CFRP). The new CFRP material is strong and lightweight but, unlike metal, doesn’t propagate damage when impacted. For example, when a conventional vehicle get into an accident, the stresses from the impact aren’t limited to just the area of the impact, but spreads through different parts of the vehicle, because metal tends to transmit energy. The BMW i3’s CFRP safety cell doesn’t transmit this energy, so the damage is limited to just the area of the impact.
Here’s a video of the BMW i3 being put together in the factory. The same easy assembly can be repeated at the body shop in case of an accident…
BMW recognizes that the materials themselves, CFRP and high-strength resin adhesives, are more expensive than metal parts, but the amount of time to repair a section of the safety cell is greatly reduced. The safety cell of the BMW i3 is made up of some 35 different parts that can be easily cut out and replaced. According to BMW, this will cut down on insurance costs, which reduces the overall price of this new extended-range electric vehicle. This isn’t a one-shot deal, however, as BMW plans on implementing this technology in more vehicles across its lineup, improving fuel economy and reducing insurance and repair costs.
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