A Formula 3 racing car made entirely out of recycled and renewable materials could be a sign of things to come in the automotive industry. At least, that is the hope of some British researchers who have built WorldFirst, an unusual automobile made mostly using recycled plastic water and juice bottles, potato starch, carrot fibers and other materials one normally expects to find in the recycling or compost bin.

The car reaches a top speed of 238 kilometers per hour and has been driven more than 800 kilometers for testing and demonstrations since it first rolled out of the lab in April. WorldFirst was tested at Brands Hatch—a motor racing circuit in Kent, England—driven by professional racer Aaron Steele.

Engineers at the Warwick Innovative Manufacturing Research Center (WIMRC) at Warwick University in England built the car as part of a larger project to develop new materials for use in the automotive and health care sectors that meet the goals of sustainable development. The WorldFirst racing car also is a response to two emerging trends in auto racing: an interest in a greener approach to the sport and the escalating costs of fielding a competitive Formula 1 racing team that have chased away some sponsors, says James Meredith, a WIMRC biomaterials engineer and WorldFirst project manager. (Formula 3 competitions are generally considered to be stepping-stones for drivers looking to compete in Formula 1 races.)

The WorldFirst car is a proof-of-principle vehicle that shows it is possible to use recycled and reused materials to build a functioning automobile. "The choice of which materials to use was based on how easy they were to work with, what shape the part we needed to manufacture was, and what mechanical properties were needed," Meredith says. Recycled carbon fiber was used for the large parts of the car such as the engine cover. Fibers made from flax and hemp were used for simple parts such as the bargeboard and bib, which are used to improve aerodynamics. Other major parts of the car are made from carbon and fiberglass.

The outer part of the steering wheel was made from Curran, a polymer made by CelluComp in Scotland and derived from carrots and other root vegetables. Curran has properties similar to those of glass or carbon fiber-reinforced polymer, Meredith says. The inside of the driver's seat was made from soy-based foam, while the cover consists of a fabric made from flax.

The tires are still made of rubber, although tire manufacturer Avon Tyres (a division of Cooper Tire & Rubber Co.) claims it is working to eliminate one of the biggest toxic polluting compounds in them, polycyclic aromatic hydrocarbons (PAH), which are used to help soften the rubber. PAHs that leach from old tires disposed of incorrectly can contaminate soil and water, and the chemical compound can become airborne in tire fires.

The WorldFirst racing car runs on biodiesel derived from chocolate fat. Meredith notes that the chocolate fat used for this purpose is actually a waste product in the food industry. "Whenever you burn a biodiesel made from waste materials," he says, "it can be argued that it is carbon neutral."
The radiator is coated with PremAir, a catalyst material that converts the ozone portion of the car's emissions into oxygen—something that is desirable since at ground level ozone is a pollutant.
How strong and how durable are the materials in this car? "In terms of their durability—we are still working on this," Meredith says. "All the parts we have made to date are still going strong. Natural fibers will most likely have a lower resistance to weather effects as the fibers will absorb moisture if exposed and then degrade. Recycled carbon fiber and glass fiber with recycled resins should have equal durability to standard materials."

Biofiber components derived from a variety of plants are already being used in some non-racing car components, says Mohini Sain, a professor of forestry at the University of Toronto's Center for Biocomposites and Biomaterials Processing. Some manufacturers use biomaterials in door panels, consoles, tire covers and floor mats. Eventually, as the technology improves, biomaterials will be used in larger components, says Sain, who was not part of the WorldFirst project. Already, some biofiber materials perform as well as glass fibers and are less dense. Sain notes that biofibers do break down when exposed to moisture, but the fibers are coated in resins and plastics to counter this.

Meredith predicts the car should last as long as any other racing car, saying, "The natural fiber parts have lasted well although their weather resistance does not appear to be as good as existing materials." In the end, "ideally all the natural fiber products can be shredded and composted, carbon parts can be recycled again—albeit with a small amount of degradation," he adds.