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The value of carbon fiber is obvious: it's light, it's strong, and, for luxury and performance enthusiasts, it carries a certain cachet of exclusivity. That last factor may be changing as wider use is made, but it's still attractive in its own right, and its lightweight structural virtues are nearly inimitable.
As BMW's Friedrich Eichiner put it, "Lightweight construction will play an increasingly important role in the automobile industry in the future. Our stake-holding in the SGL Group is a logical step…"
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Mercedes-Benz has made its own partnership in the carbon fiber field, with leading Japanese manufacturer Toray. That partnership is expected to yield CFRP and carbon fiber parts for more conventional vehicles than BMW's i range. The 2013 Mercedes-Benz SL-Class is expected to be the first to benefit from the Toray deal.
Audi, likewise, has teamed up with Germany's Voith to source its carbon fiber materials and components. Unlike BMW and Mercedes, however, Audi's plans for its expanded carbon fiber use haven't been as explicitly disclosed.
Even as carbon fiber rises in popularity and availability, however, manufacturers aren't leaving aluminum and steel for dead. Quite the opposite, with all three leading German luxury carmakers, plus most mainstream carmakers employing new alloys in every-increasing variety within a single vehicle to suit structural, NVH, and impact needs.
Ferrari, for instance, recently said it will be sticking with aluminum even as rivals like Lamborghini and upstart McLaren Automotive delve heavily into carbon fiber with the Aventador and MP4-12C. Production cost, complexity, and speed of construction all work in aluminum's favor, and Ferrari thinks it can still achieve its weight, rigidity, and performance goals with the lightweight metal. With many alloys for many purposes, plus a wider variety of construction methods including welding and epoxy bonding, aluminum does offer greater flexibility--for the present.
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For larger vehicles, aluminum continues to make even more sense. Audi's upcoming 2013 Q7 will shed as much as 650 pounds compared to the current model through more extensive use of aluminum in the body and chassis. Volkswagen and Porsche have already done nearly as much with the Cayenne and Touareg, which share a platform, cutting 400 pounds from their SUVs. The slightly larger Q7, which will also share the same underpinnings, can save even more weight due to its size.
Saving that much weight in a large SUV with carbon fiber at today's prices would be prohibitively expensive, however, even with the established partnerships between Volkswagen Group companies and carbon fiber makers.
As these joint ventures and partially-owned partnerships with carbon manufacturers continue, however, prices will fall, and use will become more widespread, helping carmakers reach ever-tightening fuel economy and emissions targets while--hopefully--preserving or improving vehicle dynamics even as engines in many cars downsize displacement in favor of forced induction, hybrid drive systems, and fully electric powertrains.