How Plastics Help Improve Fuel Efficiency

Go Green license plate

Sometimes big environmental improvements come from unexpected places …

While most of us know that drastically improving automobile fuel efficiency will reduce gasoline consumption and tailpipe emissions, we may be less familiar with exactly how our cars and trucks are changing to make that happen.

The U.S. government recently announced stringent new Corporate Average Fuel Economy (CAFE) standards: our nation’s cars and light trucks must average a whopping 54.5 miles per gallon by 2025. The standards not only will help reduce auto emissions—they could also save us some serious cash at the pump.

So how will automakers meet these goals? Through more aerodynamic design, improved engine efficiency—and a greater reliance on plastics. That’s right, plastics.

Perhaps unnoticed by most drivers, automakers over the past few decades have dramatically increased the use of tough, lightweight plastics, displacing heavier materials. Due to their positive strength-to-weight ratio, plastics make up an astonishing 50 percent of today’s cars by volume—but only 10 percent by weight. This “lightweighting” results in less strain on the engine and improved gas mileage. In other words, more plastics leads to less fuel use.

(And lucky for us drivers and passengers, lightweight plastics also play an integral role in many auto safety features: think seat belts, air bags, interior cushioning, crumple zones, bumpers …)

And that’s just the beginning. To satisfy CAFE standards—and Americans who still want large cars—automakers are expected to turn even harder towards plastics, throughout more of the car, using innovations in plastic “composite” materials.

These composites combine plastics with glass fibers, carbon fibers, or other materials to create car parts that often are stronger and lighter than metals, as well as corrosion-resistant. They already are in use today on some on high-end vehicles, such as the Corvette Stingray with its sleek carbon-fiber-reinforced plastic hood and roof.

And recent manufacturing breakthroughs are projected to catapult carbon fiber-reinforced plastics into the mainstream, along with similar tough, lightweight composites, by speeding production time and reducing costs. The U.S. government, auto companies and plastics makers are investing heavily in this technology, so we should expect these composites to make their way into the cars we drive every day.

Many experts predict even broader applications of plastics in future models—including plastic composites in the chassis and engine—leading to ultra-lightweight cars with even better gas mileage and lower emissions.

Now, let’s face it—all these new cars will not look as cool as the Corvette Stingray. But if and when automakers meet the CAFE standards, we collectively will have reduced auto emissions dramatically—and we hopefully will be spending a whole lot less at the pump.

While driving a car that’s made predominately with plastics.

Now, who would have expected that the answer to this big problem would be made possible with plastics? Well … other than a whole bunch of automotive engineers, that is.