The moldable synthetic materials in the GM and Swiss prototypes have fundamental advantages over the metals that now dominate auto making. The modern steel car, which costs less per pound than a McDonald's quarter-pound hamburger, skillfully satisfies often conflicting demands (to be efficient yet safe, powerful yet clean): steel is ubiquitous and familiar, and its fabrication is exquisitely evolved. Yet this standard material could be quickly displaced—as has happened before. In the 1920s the wooden framing of U.S. car bodies was rapidly displaced by steel. Today composites dominate boatbuilding and are rapidly taking over aerospace construction. Logically, cars are next.
Driving this transition are the huge capital costs of designing, tooling, manufacturing, and finishing steel cars. For a new model, a thousand engineers spend a year designing and a year making half a billion dollars' worth of car-sized steel dies, the costs of which can take many years to be recovered. This inflexible tooling in turn demands huge production runs, maroons company-busting investments if products flop, and magnifies financial risks by making product cycles go further into the future than markets can be forecast. That this process works is an astonishing accomplishment, but it's technically baroque and economically perilous.
Moldable composites must be designed in utterly different shapes. But their fibers can be aligned to resist stress and interwoven to distribute it, much as a cabinetmaker works with the grain of wood. Carbon fiber can achieve the same strength as steel at half to a third of the weight, and for many uses other fibers, such as glass and polyaramid, are as good as or better than steel and 50-85 percent cheaper. But composites' biggest advantages emerge in manufacturing.
Only 15 percent of the cost of a typical steel car part is for the steel; the other 85 percent pays for pounding, welding, and smoothing it. But composites and other molded synthetics emerge from the mold already in virtually the required shape and finish. And large, complex units can be molded in one piece, cutting the parts count to about one percent of what is now normal, and the assembly labor and space to roughly 10 percent. The lightweight, easy-to-handle parts fit together precisely. Painting—the hardest, most polluting, and costliest step in auto making, accounting for nearly half the cost of painted steel body parts—can be eliminated by laid-in-the-mold color. Unless recycled, composites last virtually forever: they don't dent, rust, or chip. They also permit advantageous car design, including frameless monocoque bodies (like an egg, the body is the structure), whose extreme stiffness improves handling and safety.
Composites are formed to the desired shape not by multiple strikes with tool-steel stamping dies but in single molding dies made of coated epoxy. These dies wear out much faster than tool-steel dies, but they're so cheap that their lack of durability doesn't matter. Total tooling cost per model is about half to a tenth that of steel, because far fewer parts are needed; because only one die set per part is needed, rather than three to seven for successive hits; and because the die materials and fabrication are much cheaper. Stereolithography—a three-dimensional process that molds the designer's computer images directly into complex solid objects overnight—can dramatically shrink tooling time. Indeed, the shorter life of epoxy tools is a fundamental strategic advantage, because it permits the rapid model changes and continuous improvement that product differentiation and market nimbleness demand—a strategy of small design teams, small production runs, a time to market of only weeks or months, rapid experimentation, maximum flexibility, and minimum financial risk.
Together these advantages cancel or overturn the apparent cost disadvantage of the composites. Carbon fiber recently cost around forty times as much per pound as sheet steel, though increased production is leading manufacturers to quote carbon prices half to a quarter of that. Yet the cost of a mass-produced composite car is probably comparable to or less than that of a steel car, at both low production volumes (like Porsche's) and high ones (like Ford's). What matters is not cost per pound but cost per car: costlier fiber is offset by cheaper, more agile manufacturing.