It all adds up - the new sliding rear window on the 2015 F-150 saves about a pound.

(The story has been updated to include results of a new survey of pickup owners.)

Ford Motor Co. is so eager to show off the innovations and weight-savings built into its aluminum-bodied 2015 F-150 pickup, it held a press conference to show off a new sliding rear window that saved just slightly less than one pound.

The maker is racing to get ready for the launch of the new truck and knows there are plenty of concerns about the switch to an “aluminum-intensive” body – made all the more of a challenge by a fire that destroyed a prototype of its next-generation heavy duty pickups, expected to switch to the lightweight metal a year after the launch of the half-ton F-150.

The 2015 pickup will be as much as 700 pounds lighter than the old, steel-bodied F-150, much of that due to the switch to aluminum. But Ford also has cut mass in a number of areas, large and small. That includes the use of a new “seamless” sliding rear window developed in a collaboration with Canadian-mega-supplier Magna International, noted the appropriately named Noah Mass, the Ford engineering manager responsible for sliding windows and sunroofs.

“Delivering the latest in innovation and technology to our customer is a top priority for Ford,” Mass said. “The seamless sliding rear window is another great example of the intricate detail that goes into producing the next-generation F-150, setting it apart from any pickup on the market today.”

The 2015 Ford F-150 will weigh in as much as 700 pounds lighter than the old, steel-bodied pickup.

Standard sliding rear windows typically contain three pieces of glass – left and right panes that don’t move plus the sliding portion in the middle, all held together by a support structure that requires numerous components. The seamless sliding rear window uses only two pieces of glass – the exterior surround and the sliding portion, reducing build componentry and complexity. The window’s opening is the same size as the outgoing design.

In addition to its streamlined looks, the window’s two-piece design enables continuous uninterrupted defrost capability for the larger surrounding glass.

Mass said the Magna design also contributes to vehicle weight savings, as the seamless power slider uses a lighter window control module. The new window structure weighs 20.74 pounds, compared to the 21.73, resulting in a small but much-appreciated weight savings.

That may not sound like much, but every gram counts –and they add up. While Ford has not released final fuel economy numbers for the 2015 F-150, the general rule of thumb is that a manufacturer gains about one mile per gallon for every 100 pounds of weight-savings. Performance and cargo capacity also improve.

(Automakers put a premium on “lightweighting.” Click Here to find out why.)

A fire rapidly spreads across a Ford Super Duty pickup prototype undergoing tests in Death Valley.

Troy Tooker. design engineering manager for Magna International, said the intellectual property behind the window belongs to Magna, which obtained patents for the technology. “We designed the seamless sliding rear window to deliver not only a new look and improved functionality, but also to start a trend in the truck sliding window market,”  Tooker said.

Tooker recalled his phone rang off its hook after Ford unveiled the 2015 F-150 at the North American International Auto Show, and other manufacturers are definitely interested in the technology.

The launch of the new F-150 has gotten plenty attention thanks in part to an aggressive media campaign by Ford’s public relations staff but also because it features so much new technology, starting with that aluminum body. High-strength, military-grade alloys are used throughout the F-150 body for the first time, improving dent and ding resistance and also saving weight, according to Ford.

(Chrysler’s Ram 1500 wins high praise from Consumer Reports. Click Here to see why.)

Despite Ford’s claims, there remain plenty of concerns, especially among fleet and individual buyers who question the long-term durability and maintenance costs of aluminum.

And Ford certainly would have preferred not to have had a “spy” photographer nearby when a prototype of its next-generation Super Duty pickup caught fire several weeks ago, a pair of Ford engineers jumping from the vehicle as it burned down to little more than a pile of molten aluminum.

(For more on the fire, Click Here.)

The destruction of the prototype, which Ford spokesman Mike Levine said is “under investigation,” demonstrated that an aluminum body can burn and melt at a significantly lower temperature than steel, producing a spectacular blaze. Steel on the other hand will survive a gasoline fire basically intact – though there may be little else left.

Ford officials are downplaying such problems. They note that when it arrives in showrooms later this year, the 2015 F-150 will have undergone the equivalent of more than 10 million miles of torture testing to ensure it meets or exceeds the standards that come with the “Built Ford Tough” slogan.

On the positive side, a recent study by UBS found pickup buyers are “extremely likely” to consider the new F-150. “We found very strong buying interest for the new F-150,” stated the report, adding that, “Interest was particularly high in the most important and informed group: pickup owners intending to buy within the next 12 months.” The survey suggested that potential buyers are not “steel loyalists,” with far more drawn to the benefits  than dissuaded by possible problems.

The most immediate challenge for Ford will be to get the new truck to market quickly even though it will be testing several new manufacturing processes. Mark Fields, Ford’s new chief executive officer, whose reputation will rise or fall with the success of the new F-150, has said the changeover of the company’s Dearborn truck assembly plant will begin at the end of August.

Ford expects to have the F-150 in showrooms before the end of the year, Levine said.