Automakers are increasingly incorporating environmentally friendly materials into their designs that have the added benefit of improving fuel economy.

By Dennis Barker

Soybeans, coconut, flax and hemp may seem like ingredients for a dish being whipped up by a chirpy TV chef, but they're actually plant products that are part of the car you'll be driving someday (if they aren't already).

To design vehicles that are friendlier toward the environment — and the family gasoline budget — automotive engineers and researchers aren't looking just under the hood. They're exploring ways to build greener cars out of natural materials that can be easily renewed and recycled, that don't pollute when being manufactured and that don't require pricey petroleum or potentially toxic chemicals to produce.

Although a soybean car won't be rolling off the assembly line any time soon, innovative researchers have proven the feasibility of using alternative materials throughout. At the University of Warwick in England, a team set out to build a car that's 95 percent biodegradable or recyclable. The body is made of hemp, brake pads are made of nut shells, and the tires are made of a substance derived from potatoes. Top speed: potentially 150 mph.

The chassis is old-school: made of steel. But steel, after all, is recyclable. And the old metal continues to advance. New technologies are producing lighter steels that promise to reduce body weight by as much as 35 percent.

Benefits of Using Natural Products for Car Parts

One of their goals is the same as designers working with traditional materials: Build a car that's lighter. Weight reduction is one of the most effective ways to increase fuel efficiency. A 10 percent weight loss cuts 0-to-60 time by about 8 percent.

Replacing steel with new bioplastics — plastics made from resins extracted from corn, soybeans, wheat or other plants, instead of oil-based substances — would be the most dramatic way to lower weight. Bioplastics might sound very 21st century, but the notion has been around since the Model T. Henry Ford expected to build car parts out of soybean, and did use hemp fibers in some body components. (As it turned out, petroleum derivatives were less expensive at the time.)

Now the idea is back and research is moving forward. Auto companies, agribusiness and governments are all looking for ways to produce the plants that will yield an environmentally friendly car.

Automakers have already begun incorporating some of these semi-exotic materials. Examples include:

• In Brazil, Mercedes uses coconut fibers to make seats, headrests and other inside parts. The fibers are tough and resilient, and breathe much better than polyurethane (goodbye sticky seats in the summer).
• Mitsubishi is using bamboo fibers and plant-based resins in some of its interiors.
• Ford in the U.K. signed a deal last year to investigate the use of hemp to replace steel, glass and plastic in its vehicles.
• Several years ago, Volvo began taking the “total environmental load” into account when choosing interior materials.
• And many automakers are already using soy-based foam in seat cushions and arm rests.

Proponents say that materials like coconuts are carbon-neutral: They emit the same amount of carbon dioxide when consumed as they captured when growing. Natural products are also easier to re-use or dispose of. As these materials become more prevalent in autos, experts expect that manufacturers will develop ways to disassemble vehicles and either re-use the parts or return them to the earth.

Expanding the Market for Green Cars

Using these materials in cars certainly would appeal to those drivers who have sought out hybrids and cars that run on greener fuels. But automakers are also trying to extend this appeal to a broader crowd by using these new materials in other cars. For example, high-performance auto designer Lotus has shown the Eco Elise, with body panels made of hemp and sisal, coated with water-based paints, and equipped with a solar panel in the hemp roof to power the electrical system. Lotus says the Eco Elise weighs 70 pounds less than its non-plant-based counterpart, the Elise S.

The net result of all of these efforts is that the concept has been proven: Cars can be made out of earth-friendly materials and be lighter, both in weight an on the gas budget. Manufacturers will have to re-tool to completely embrace the use of natural substances. That's not easy, that's not cheap, and it's not done overnight. Producers will also have to come up with ways to reprocess these materials on a large scale. But the transition has begun.

Bio: Dennis Barker has been writing about science and technology for more than 20 years. During that time he has served as an editor at several leading computer and technology industry publications.