While most major automakers have already dropped broad hints about what they'll reveal at the Detroit auto show this month, Ford has been unusually quiet about its unveiling at the annual show. It is likely to be big: an all-new version of the maker's best-selling truck, the F-150.
The update is not just a restyled pickup with a few more features, either. The 2015 Ford F-Series should mark a dramatic shift in a segment that has come roaring back over the last 12 months, with the Detroit automaker expected to choose an aluminum-intensive design hundreds of pounds lighter than the outgoing pickup. In the process, fuel consumption will be improved by perhaps 5 mpg.
(Slideshow: 10 hottest cars at the LA Auto Show)
That said, the automaker could face a serious challenge with a redesign of what has long been America's best-selling vehicle. Even though buyers in every market segment are demanding better mileage, the question is whether those in the pickup segment will feel comfortable with a major shift from rugged, time-tested steel. Ford will have to convince potential buyers that they'll not only save fuel but get a durable truck that won't offset those savings with higher maintenance costs.
The company hinted at what was coming when it revealed the Atlas Concept during the 2013 North American International Auto Show.
(Read more from The Detroit Bureau: Automakers Buoying German Economy)
"Part of our strategy is to put all our vehicles on a diet," Ford Chief Operating Officer Mark Fields told TheDetroitBureau.com, adding that the goal is to remove from 250 to 750 pounds from each product. Insiders say that the higher figure was the target for the F-Series remake, though how successful Ford was in reaching that goal remains to be seen.
Ford is by no means the only automaker struggling to cut weight. The rough rule of thumb is that fuel economy rises by about one mpg for every 100 pounds of mass removed from a vehicle. That could prove critical in meeting the tough federal mileage mandates that go into effect in 2016 and 2025.
(Read more from The Detroit Bureau: McLaren, Mercedes Take Wipers High Tech)
Curbing weight is complicated by other regulatory changes, especially in the form of tougher crash standards that generally mean adding more metal to protect passengers. Consumers are also pushing the industry in the opposite direction, demanding more content in the vehicles they buy.
Another challenge is cost. Though it's heavy, steel is strong and relatively cheap compared with aluminum and even more exotic carbon fiber. Nonetheless, manufacturers are migrating to new materials at a quickening pace, as Ford's new F-Series will demonstrate to the world.
(Read more: 'Stop-start' technology to become norm)
But consumer resistance may be Ford's biggest obstacle. The maker shouldn't have a problem pitching the benefits of a lighter, more fuel-efficient truck. But pickup buyers are generally a cautious lot who want to be sure that their vehicles will keep running no matter what. And with a large share of trucks sold to fleet customers, operating costs are scrutinized closely.
Ford will have to assure potential shoppers that the new F-Series is at least as rugged and reliable as what it's replacing.
"Ford's sales job will be considerable," said a story by Bloomberg News Service, which added that the maker and its materials supplier, Alcoa, will use aluminum extensively at its stand at the auto show to get visitors more comfortable with the metal.
(Read more from The Detroit Bureau: BMW,Toyota Pledge to Make Two Sports Cars)
Despite such concerns, industry analysts note that other manufacturers have successfully made the move to aluminum. For example, most Jaguar and Audi vehicles use aluminum-intensive designs.
An even better example could be Land Rover, the British manufacturer known for its go-anywhere sport-utility vehicles. The company adopted an aluminum body and frame for both the 2013 Range Rover and this year's Range Rover Sport, saving as much as 800 pounds. If anything, Land Rover said, the new vehicles have enhanced their legendary off-road capabilities.
(Read more: Ford profit warning clears deck for 2014)
Can Ford win over pickup buyers? If it does, significantly better mileage could prove to be a major advantage over well-reviewed competitors such as the all-new Chevrolet Silverado and the Ram 1500 pickup, which was recently named Motor Trend's Truck of the Year. Ford could force its competitors to quickly redesign their own vehicles to catch up.
If not, the F-Series could wind up slipping from its exalted perch as not only the best-selling truck in America but the best-selling vehicle overall for the past three decades.
—By CNBC Contributor Paul A. Eisenstein. Follow him on Twitter @DetroitBureau or at thedetroitbureau.com.