The advent of the 2015 Ford F-150 pickup has monopolized the aluminum vs. steel debate, and understandably so.
The F-150, with its aluminum cab and cargo box, could be a rolling advertisement for Alcoa, Ford's chief aluminum supplier.
But the fuss over the F-150 obscures a deeper trend: Step by step, automakers are making greater use of aluminum hoods, fenders, doors, liftgates and roofs.
And the transition is occurring across the board, although pickups, SUVs and full-sized sedans are getting most of the action.
The shift is gaining momentum, according to a report last month by Ducker Worldwide, a suburban Detroit consulting firm.
In 2015, the average vehicle will have 394 pounds of aluminum parts, up from 350 pounds in 2012. By 2025, the average vehicle will have an estimated 547 pounds of aluminum, according to the report.
Pickups such as the F-150 will account for a big chunk of the aluminum used, but every vehicle class will get its share. In North America by 2025, the report predicts that aluminum will be the chosen material for:
85 percent of hoods
46 percent of doors
33 percent of trunk lids and liftgates
30 percent of roofs
27 percent of fenders.
Automakers are accelerating the shift to aluminum in part because they've gained so much manufacturing experience with it over the past decade or so.
Here's another variable. Federal regulators based their corporate average fuel economy goal of 54.5 mpg by the 2025 model year on the assumption that 25 to 30 percent of vehicles sold by 2025 would have a hybrid engine, electric motor or some other alternative powertrain.
Based on market share trends for hybrids, it's unclear whether automakers will hit that target, said Dick Schultz, managing director of Ducker Worldwide and author of the report.
"If we don't start adopting hybrids more quickly, there will be more pressure to produce lightweight parts," Schultz said.
Schultz believes the F-150 is a big deal. "If the F-150 is successful, the other producers will have to follow it," Schultz said. "It's the next new thing."
But for most vehicles, automakers are going to make an incremental switch to aluminum -- one component at a time. "It won't be all or nothing," Schultz said. "This isn't some kind of death knell for steel."