Autovolt Magazine

BMW i8 Carbon Fibre

BMW continues their camp videos with new explanations and footage of the carbon fibre used in the construction of both the i3 and i8 vehicles.

Carbon fibre is not a new material, but it is more costly to use than alternatives since it requires a more complicated production. As such it has been the reserve of airplanes, racing cars and boats plus space craft too.

Being a composite material, the way it achieves it’s properties is much the same as an alloy might take features from it’s core elements. The carbon weave is set within a resin which is then set to become a very rigid material. The carbon weave gives the signature black property and holds the plastic together. Another analogy could be that of reinforced concrete where intertwined steel rods are created and then flooded with concrete. In that analogy, the carbon material would be the steel rods and the plastic resin the concrete.

Thus Carbon Reinforced Plastic or CFRP is created and put to great use by BMW as stated in the video – the BMW i8 weighs only 1490 kg. To put that into perspective, a very popular super mini’s gross vehicle weight is over 1500 kg. Not only that but since the i8 is a hybrid vehicle, they tend to weigh in more than a car that is only propelled by a single powerplant. As such, the i8’s weight is more comparable to that of a non-hybrid vehicle, due in part to the weight saving made by using carbon fibre.

Carbon fibre is significant in it’s use by BMW in their production i-series cars as, up until now, CFRP has been reserved for more bespoke vehicles due to the cost. BMW have changed that with the i3 in particular which extensively uses carbon fibre. The BMW i8 uses CFRP in a similar way, but the vehicle costs a lot more to purchase than the i3.

Overall, the properties of carbon fibre mean that it is tough yet flexible and light yet rigid. The strength to weight ratio of CFRP means that vehicle manufacturers wanting a strong vehicle for both safety and handling characteristics, but light weight so that cornering and performance are not hindered need look no further.

As an added bonus, BMW have designed the carbon fibre elements of their i cars to be almost 100% recyclable.

BMW i8 carbon fibre

Video source; BMW