How pickups could lose 800 pounds with aluminum
OK, so automakers are designing sedans that can get 35, 40 or even 50 mpg. But what about full-sized pickups?
You can't shrink a pickup too much or it can't haul 4-by-8 plywood sheets, and an engine that's too small can't tow big loads.
Federal regulators "are pretty confident" that cars will meet CAFE requirements, "but trucks are going to be more of a challenge," says Dick Schultz, an analyst for Ducker Worldwide, a consulting firm based in suburban Detroit.
With the judicious use of aluminum and magnesium, it appears that automakers can reduce a pickup's weight by about 800 pounds without degrading performance.
Last year Schultz was the author of a survey report that listed a variety of weight-saving strategies for pickups. For his base case, Schultz chose a 2008 Dodge Ram quad cab SLT pickup that weighed 5,075 pounds.
He hypothesized three weight reduction scenarios - basic, mid-range and extreme, each with a cost estimate. Under the most costly extreme scenario, Schultz estimated that the Ram's weight could be reduced by nearly 800 pounds at an added cost of about $1,700.
An 800-pound weight reduction - plus some major powertrain changes - would go a long way toward meeting federal CAFE targets.
Schultz speculated that a 4,000-pound pickup could achieve a fuel economy of 33 mpg. Not bad, but Schultz offers a few caveats.
1. Schultz did not specify the necessary powertrain improvements, which were outside the scope of his survey.
2. The survey did not evaluate lightweight polymers and composites for certain parts. Automakers clearly will consider these and other materials.
3. Chrysler and other automakers already have adopted some of Schultz's suggestions. For example, the 2013 Dodge Ram 1500 pickup has an aluminum hood - which saved 26 pounds - and aluminum lower control arms. And high-strength steel in the frame saves another 30 pounds.
With all that in mind, here's a selection of steel components in the 2008-model Dodge Ram, along with the substitute material and weight savings:
Cab: An aluminum body-in-white cab would weigh 285 pounds, saving 190 pounds.
Cargo box: An aluminum cargo box would weigh 171 pounds, saving 114 pounds.
Doors, tailgate: Magnesium inner door panels would weigh 62 pounds, saving 63 pounds.
Suspension arms and links: Aluminum components would weigh 60 pounds, saving 60 pounds.
Seat frames: Magnesium seat frames would weigh 18.5 pounds, saving 26 pounds.
Radiator support: A magnesium radiator support would weigh 28 pounds, saving 27 pounds.
Bumpers: Aluminum bumpers would weigh 54 pounds, saving 36 pounds.
You can reach David Sedgwick at email@example.com.