Steel Industry to Aluminum: Our Green Auto Bodies Can Match Yours

Steel Industry to Aluminum: Our Green Auto Bodies Can Match Yours

In the race to design more fuel-efficient vehicles, there's a battle brewing over which auto body materials produce the greenest cars.

The automotive arm of the steel industry recently declared itself a contender for the title in the competition where lightweights seemingly have the edge.

No problem, says the auto steel biz, which ballyhooed the results of a three-year lifecycle analysis project at the Frankfurt Motor Show last week.

For the project, advanced high-strength, lower-weight, steel-intensive bodies were designed for four types of electric vehicles, according to the World Steel Association's WorldAutoSteel group and the engineering firm EDAG International.

The so-called FutureSteelVehicles incorporated the advanced designs for bodies of a battery electric vehicle, a plug-in hybrid, a mid-size plug EV and a mid-size fuel cell electric car that are proposed for 2015 to 2020.

The report said the body weights of the FSV designs for the battery and fuel cell cars matched those of aluminum auto bodies designed for the same vehicles. Also, the LCA showed that lifecycle emissions for the FSVs were 70 percent lower than those of comparably sized cars with internal combustion engines, the trade association and the engineering firm said.

WorldAutoSteel Director Cees ten Broek said the research demonstrates the importance of lifecycle assessments in measuring vehicles emissions. Focusing on weight and tailpipe emissions can be deceiving, he suggested.

"When vehicle emissions assessments are focused solely on what comes out of the tailpipe, this encourages use of low-density, greenhouse gas-intensive materials that may provide lighter weight components to improve tailpipe emissions," ten Broek said in a prepared statement. "However, their greenhouse gas intensity may have the unintended consequence of increasing greenhouse gas emissions on a lifecycle basis."

Aluminum Industry Extolls Its Metal of Choice

The FSV study results were initially released in May in Brussels, and their presentation at the Frankfurt Motor Show came just one week after Aluminum Association' transportation group released research (pdf) touting the attributes of that lightweight metal.

In the push to improve fuel economy, automakers have increasingly turned to aluminum to lighten the weight of vehicles in the past 40 years, according to the survey conducted in North America by Ducker Worldwide for the trade group.

The average amount used in cars is expected to hit 343 pounds per vehicle in 2012 -- that's 5 percent more than the average of 327 pounds per vehicle in 2009. The report also projected that use of aluminum in the auto industry will continue to grow -- reaching an estimated average of 550 pounds in cars and light trucks by 2025 -- as carmakers try to further reduce vehicle weight by at least 10 percent.

Aluminum is already the metal of choice for powertrains and wheels, and its use in hoods, trunks and doors is on the rise, said the report, which took a slap at advanced high strength steel, the stuff in the FSVs:

"Advanced High Strength Steels ... are growing at the expense of inferior steels, but gauge reduction with AHSS provides limited weight savings potential compared to using lower density aluminum. Pound for pound, aluminum replaces more than twice as much weight as AHSS."

Other Green Car and Materials Research

It's been a big year for green car research and materials development. In a report in June, engineering tech firm Ricardo concluded that while the production of hybrid and electric cars creates more carbon emissions than standard autos, HEVs and EVs are nevertheless greener overall -- despite criticism to the contrary.

In March, Brazilian scientists made headlines when they said they found a way to turn fibers from pineapples, bananas, coconut shells and other plants into plastics that can be used in carmaking for everything from dashboards to bumpers.

And the future may bring even more materials-based sparring, should the plastics industry weigh in at full strength. Just this spring, UPS rolled out a prototype for a plastic delivery truck that's expected to deliver a 40 percent improvement in fuel efficiency.

Image courtesy of the FutureSteel Vehicle Initiative.