How do you make a 4,685-pound truck use 25 percent less fuel? By making it a 3,985-pound truck - at least according to Ford.
The automaker has said that, in an effort to improve fuel efficiency, it is considering using aluminum instead of steel for key parts of its signature F-150 truck line, trimming around 700 pounds from the vehicles’ weight. The proposal is part of the scramble among automakers to meet stringent new federal fuel efficiency standards, which will be phased in starting in 2017. By 2025, the standards will require automakers to double efficiency.
The standards were controversial when President Obama announced them last year. In the end, however, the president managed to get 13 major automakers to back the proposal in principle, though the carmakers have still pushed for significant changes in the way the proposal will be implemented.
Obama’s standards require only that new car models use less gas; they don’t say how. They don’t require that new models contribute to lower oil consumption overall or that they be any better for the environment. The Ford F-150 redesign may not do either of those things.
While aluminum parts help to reduce a car's fuel consumption and emissions, aluminum production generates around 10 times as much carbon dioxide as steel production, according to a 1999 MIT report. The report found that, once production of raw materials is factored in, aluminum-bodied cars actually produce higher emissions than lightweight steel ones. Each aluminum-based car would need to be on the road for 32 to 38 years in order for the lower emissions of the final vehicle to offset the difference in emissions during production, according to the report.
Assembling aluminum cars is also more energy-intensive, since aluminum, unlike steel, is not magnetic. Automakers must use huge, electricity-hogging vacuums to move aluminum parts, while steel parts can be easily picked up with magnets.
The aluminum industry claims that the metal’s possible sustainability failings are made up for by its recyclability. Two-thirds of the aluminum ever produced remains in use today, according to the Aluminum Association, an industry group whose mission statement is to “aggressively promote aluminum as the most sustainable and recyclable automotive, packaging and construction material in today’s market.”
There are, however, only so many soda cans out there to be crushed down and turned into car parts. While the Aluminum Association trumpets the fact that 1.56 billion pounds of used beverage cans were recycled in 2008, the transportation industry consumed over 6 billion pounds of aluminum that same year. A further increase in demand could make recycled aluminum a much smaller portion of overall consumption. Novelis, the world leader in rolled sheet aluminum, is already tripling its U.S. production of the sort of aluminum used by the automotive industry.
An increase in demand could also spur a spike in prices. Recently, aluminum prices have been at two-year lows because of a supply glut. Ford’s proposed use of aluminum in its F-Series trucks could go a long way toward changing that. At one time, Ford F-series truck sales accounted for 5.5 percent of all U.S. vehicle sales; while sales have declined since then, the company still sold nearly 600,000 of the vehicles last year.
If aluminum prices do increase, beverage packagers may rely more on plastic - which, of course, is made from petroleum. Less oil would go into cars, but more would go into holding Coke and Pepsi. Fewer aluminum cans being produced would also mean fewer coming back to be recycled.
I don't know what net effect Ford’s move to aluminum would have on the environment. The administration was equally in the dark when it pushed the new fuel standards without knowing how automakers would achieve them. The new standards may end up being a good thing. They may not. Only time will tell.
August 28, 2012 - 9:44 am
I read with interest your post this week about the environmental impact of using aluminum to reduce vehicle weight in an effort meet higher fuel economy targets, and wanted to follow up with you. I am the chairman of the Aluminum Association’s Aluminum Transportation Group (ATG) – we have a substantial amount of information that discredits the decade-plus-old MIT study you reference in your piece and would like to offer newer, more credible data.
In short, the MIT report was biased and flawed. It was sponsored by the steel industry and based on the unrealistic premise that additional aluminum produced for the automotive industry after 1999 would be 100 percent derived from coal-powered electricity and would only be sourced from primary aluminum. Neither of these assertions is true. In fact, since 1999, the only new primary aluminum smelter in North America is based on hydro-powered electricity, and looking forward, all expansion announcements (not yet implemented) have been also based on hydro-powered electricity. Further, a 2006 study reported that nearly 60 percent of the aluminum content in North America was from recycled aluminum.
In 2010, a truly independent study of the issue, conducted under the sponsorship of the governments of Canada, China and the United States for the magnesium industry, concluded that – better than either steel or magnesium – automotive aluminum achieves the best lifetime performance for lowest overall energy use and greenhouse gas emissions. This independent and up-to-date study confirmed automotive aluminum consumes 20 percent less total energy overall than steel, and produces 20 percent fewer emissions than steel due to the energy saved with aluminum in the automobile’s usage phase (decreased emissions from a lighter vehicle more than offset emissions produced in the production phase).
I encourage you to review this data, and we would be happy to be a resource to you in the future, should you revisit this topic. Aluminum solutions are fast-becoming central to a more holistic approach to engineering cars and trucks with lighter yet stronger materials, advanced powertrains and cleaner fuels that improve fuel economy and reduce emissions while remaining safe, durable, high performing and affordable.