Ford will keep its aluminum for trucks because using the lightweight material on other vehicles won't necessarily be worth the expense, according to Ford executive Joe Hinrichs.

The American automaker is spending $1 billion to retrofit facilities to produce an aluminum-bodied F-150; the model is a big player for Ford since it has long been America's bestselling pickup. Truck sales are estimated to make up 90 percent of Ford's profit worldwide.

But according to Hinrichs, investing in aluminum for other models wouldn't pay off.

"One of the big benefits you get from lightweighting on trucks is you give customers more capability that they want. You can tow more, you can haul more, you can do more of those things by taking the weight out," said Hinrichs, Ford's president of the Americas, as quoted by Automotive News.  

"You don't get those same benefits to a consumer on a car side. So truck buyers will pay for more capability. Car buyers will pay for better fuel economy, but there's other ways to get fuel economy in a car."

The newly aluminum F-150 is 700 pounds lighter than its predecessor and offers improved gas mileage. Ford announced estimated mileage ratings for the new F-150 in late November; the version equipped with a 2.7-liter turbocharged V-6 engine gets 19 miles per gallon in the city, 26 mpg on the highway and 22 mpg combined.

The most fuel-efficient version of the 2014 Ford F-150 gets 16 mpg in the city, 22 mpg on the highway and 18 mpg combined, according to EPA-estimated ratings. 

Ford is also working with carbon fiber, another lightweight option. On Monday, the automaker unveiled the Mustang Shelby GT 350R at the auto show in Detroit. The track-ready model has carbon-fiber wheels that shave off 52 pounds--although its everything-must-go approach that takes out the air conditioning, stereo system and other items deemed unnecessary probably wouldn't fly in a high-volume production vehicle.

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