Ford's new 2015 F-150 is expected to arrive at dealers late this year. The new truck is much lighter than the models it will replace, and will be more fuel-efficient, Ford says. Source: Ford.

We've been hearing for months that the all-new-for-2015 Ford (F 0.69%) F-150 pickup will be a lot lighter than the current model, thanks to its aluminum construction.

Ford says that some versions of the new truck will weigh as much as 700 pounds less than their 2014 counterparts. The automaker expects that weight loss to translate into better handling, more towing capacity, and, most important, better fuel economy.

Ford CEO Mark Fields has said that the new truck's fuel economy will be good enough to boost Ford's Corporate Average Fuel Economy rating. That's huge for the Blue Oval.

But will it win the all-important marketing war against the top fuel sippers from General Motors (GM 1.20%) and Fiat Chrysler (NASDAQOTH: FIATY)?

Ford certainly hopes so -- and executives aren't leaving it entirely to chance.

A "ringer" truck to win the war over fuel-economy claims?
The company hasn't yet released all of the details on its new trucks. But last week, Ford dealers were given access to the "ordering guide" for the all-new 2015 F-150 -- and it includes a special package that might be a fuel-economy "ringer." 

According to an Automotive News report, Ford will offer a "Superior Fuel Economy," or SFE, package on XL and XLT versions of the new truck, in regular or super cab configurations. Ford spokeman Mike Levine said the company expects the XL and XLT models to account for about 70% of total F-150 sales.

So what's in it? According to the order guide, the SFE package will include Ford's new 2.7-liter EcoBoost V6, as well as 17-inch wheels -- the smallest available on the 2015 F-150 -- and a special tonneau cover. (Other features may be included in the package that aren't listed in the current version of the order guide. Ford isn't saying.) 

The 17-inch wheels may be lighter than the larger versions, which could help fuel economy slightly. And the tonneau cover is likely meant to improve the truck's aerodynamic profile, which will also help save gas -- particularly at highway speeds.

Long story short, the SFE package looks like an option that could squeeze another one or two miles per gallon out of the new F-150, particularly on the EPA's highway fuel-economy ratings. 

But Ford has been clear that all versions of the new 2015 F-150 will be more fuel efficient than their 2014 counterparts, thanks to the dramatic improvements in weight. Why offer a package that makes such a small additional difference?

Here's why: bragging rights. 

A tiny advantage can mean a lot
That's not meant to be dismissive. Bragging rights -- or put another way, the ability to claim that a truck is the most fuel-efficient pickup in its class -- are a big deal, one that could give Ford (or any other truck maker) an advantage in winning sales from cost-conscious consumers, including corporate fleet buyers.

That's worth spending some money on, and that's probably why Ford created the SFE package -- even though its new trucks are already more efficient than the current models and likely to be very competitive with key rivals.

Right now, Ford is up against GM's new-for-2014 Chevy Silverado and GMC Sierra, which get an EPA-rated 24 miles per gallon on the highway in their most efficient versions, and a "High Fuel Efficiency," or HFE, package offered on Chrysler's Ram 1500.

Chrysler's HFE package is very similar to what Ford plans to offer. It includes 17-inch wheels, a tonneau cover, and special shutters for the truck's grill that help reduce aerodynamic drag, along with a 3.6-liter V6 with stop-start technology and the company's advanced eight-speed transmission. It's good for an EPA-rated 18 miles per gallon city and 25 highway, slightly better than the basic V6 Rams.

That's what Ford hopes to beat. My guess is that a 2015 F-150 with the SFE package will do just a bit better than Chrysler's HFE -- enough to give Ford the right to say that its new truck has "best in class" fuel economy.

But what about Chrysler's EcoDiesel?
Chrysler also offers a diesel version of its Ram 1500, the Ram 1500 EcoDiesel, that gets 28 miles per gallon on the highway, according to EPA estimates. That's the real mileage champ among full-sized pickups at the moment. Will Ford beat that?

Chrysler introduced a diesel-powered version of its Ram 1500 earlier this year. Sales have been strong. Source: Fiat Chrysler Automobiles.

It seems unlikely that a gasoline-powered F-150 will top the diesel Ram. But Ford can argue that the diesel Ram is in a different class, with some justification. 

Diesel fuel is more expensive than gasoline (at least in the U.S.), and modern clean-diesel engines come with added expenses and requirements. Not all truck buyers are willing to make the commitment that comes with diesel ownership.

For those who are, the Ram EcoDiesel is proving a popular choice. But for everyone else, the new F-150 with SFE could end up being the fuel-economy top dog -- at least for a while.