DEARBORN, Mich. -- Roofs made of carbon fiber. Plastic windshields. Bumpers fashioned out of aluminum foam.
What sounds like a science experiment could be your next car.
While hybrids and electrics may grab the headlines, the real frontier in fuel economy is the switch to lighter materials.
Automakers have been experimenting for decades with lightweighting, as the practice is known, but the effort is gaining urgency with the adoption of tougher gas mileage standards. To meet the government's goal of nearly doubling average fuel economy to 45 mpg by 2025, cars need to lose some serious pounds.
Lighter doesn't mean less safe. Cars with new materials are already acing government crash tests. Around 30 percent of new vehicles already have hoods made of aluminum, which can absorb the same amount of impact as steel. Some car companies are teaming up with airplane makers, which have years of crash simulation data for lightweight materials.
Ford gave a glimpse of the future last week with a lightweight Fusion car. The prototype, developed with the U.S. Department of Energy, is about 800 pounds lighter than a typical Fusion thanks to dozens of changes in parts and materials.
The instrument panel consists of a carbon fiber and nylon composite instead of steel. The rear window is made from the same tough but thin plastic that covers your cellphone.
The car has aluminum brake rotors that are 39 percent lighter than cast iron ones and carbon fiber wheels that weigh 42 percent less than aluminum ones.
Because it's lighter, the prototype can use the same small engine as Ford's subcompact Fiesta, which gets an estimated 45 mpg on the highway.
The car won't be in dealerships anytime soon. For one thing, it's prohibitively expensive. Its seats, for example, cost up to $73 apiece because they have carbon fiber frames. The same seats with steel frames are $12.
Still, prototypes are helping Ford and other companies figure out the ideal mix of materials.
"These are the technologies that will creep into vehicles in the next three to five years," said Matt Zaluzec, Ford's technical leader for materials and manufacturing research.
Some vehicles have already made a lightweight leap. Land Rover's 2013 Range Rover, which went on sale last year, dropped around 700 pounds with its all-aluminum body, while the new Acura MDX shed 275 pounds thanks to increased use of high-strength steel, aluminum and magnesium.
Ford has unveiled an aluminum-body 2015 F-150 pickup, which shaves up to 700 pounds off the current version. The truck goes on sale later this year.
The average vehicle has gained more than 800 pounds over the last 12 years and now tops out at just over 3,900 pounds, according to government data. Not only have cars gotten bigger, but safety features like air bags and more crash-resistant frames have also added weight. General Motors' Chevrolet Volt electric car has to drag around a 400-pound battery.
Morgan Stanley estimates than shaving 110 pounds off each of the 1 billion cars on the world's roads could save $40 billion in fuel each year.
"Lightweighting is going to be with us for a long time," said Hesham Ezzat, a technical fellow at GM. "Every manufacturer is going to have to leverage their entire palette of materials."