LIGHTWEIGHTING: Swapping out heavy materials for lighter alternatives can help a given car go further on a gallon of gasoline.
Image: Flickr/Bandal
When it comes to improving fuel economy, engines, powertrains, fuels and batteries seem to get all the attention.
But what about the car's traditional steel side panel or rooftop?
Using advanced lightweight materials on even the most basic car parts can improve overall fuel efficiency, too. According to the Department of Energy, reducing a vehicle's weight by 10 percent can improve fuel economy by 6 to 8 percent.
Steel has traditionally made up about 60 percent of a vehicle's total weight. But in order to meet consumer demands and increasingly stringent federal fuel economy standards, automakers are looking to alternatives, including advanced high-strength steel, aluminum, magnesium and carbon fiber.
Lightweight materials are a cost-effective way to boost fuel efficiency on conventional combustion engine vehicles and advanced automobiles like hybrids, electric vehicles and hydrogen fuel-cell vehicles.
"There are literally hundreds of different technologies that can be brought to bear to help improve fuel efficiency, but all of them begin with lightweighting," said Kevin Lowery, a spokesman with the aluminum company Alcoa Inc.
Luxury vehicles, like the Audi A8 sedan, have been using lightweight materials for years so that the car could take on a larger powertrain without adding weight and compromising on horsepower. But a new push for better fuel efficiency across the passenger vehicle fleet has more automakers using these materials across their lineup.
New federal fuel economy standards will require automakers to improve fleet efficiency to 54.5 mpg by 2025. Building upon that progress, Energy Secretary Steven Chu announced seven new research projects last month to accelerate the development of stronger and lighter automotive materials for cars and trucks.
"With strong, lightweight materials, we have an opportunity to dramatically increase vehicle fuel economy while helping America maintain its competitive edge in automotive design and manufacturing," he said following the announcement.
Aluminum in demand; steel gets stronger
Aluminum is the second-most common material in cars on the roads today after steel. But auto manufacturers have said they intend to double their use of aluminum by 2025, Lowrey said.
Ford Motor Co. announced this year it is looking to make the body of its popular F-150 light-duty truck largely out of aluminum, which would reduce the truck's weight by about 700 pounds and produce about 10 percent in fuel savings. On a hybrid vehicle, aluminum could improve the fuel economy by more than 13 percent compared to an equivalent car made of steel, according to Alcoa.
"There's not an OEM [original equipment manufacturer] anywhere in the world that isn't, as we speak, talking to an aluminum company," he said. "In years past, it wasn't that way."
Car components made of aluminum are anywhere between 10 and 40 percent lighter than conventional steel. But aluminum is about 35 percent more expensive than steel, and concerns linger that it might not be as durable.
So steel is still in the game. And new advanced high-strength steels can actually provide up to 35 percent in weight savings, according to the Steel Market Development Institute (SMDI).
The industry achieved these gains using a different chemistry to produce a stronger but more formable type of steel, dubbed "dual phase steel." Making these steels didn't add much any extra cost because it simply required changing the cooling rates on existing process lines, said Ronald Krupitzer, vice president of automotive applications for SMDI.
The industry can now make multiple types of steel that are two to three times stronger than they were a decade ago.
"If you make a component stronger, it can carry the same load as it did before, but you don't need as much steel to do it. You can make parts thinner, but they can absorb the same about of energy and hold the same load," Krupitzer said.
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13 Comments
Add CommentSounds like higher mileage at the cost of higher fatalities. is this the tradeoff we want?
Reply | Report Abuse | Link to thiszsingerb,
Reply | Report Abuse | Link to thisYou might find some basic information on the effects of using these lighter materials in an online article, like the one that is 3 inches above where you posted your comment.
If you don't believe lightweight cars can be safe - I suggest you google "F1 2012 crash Spa". If the tubs had been steel there would have been many deaths.
Reply | Report Abuse | Link to thiszsingerb, HELLO?!!! OK, smart guy. Here is a question, just for you. If I take out 35% of the weight out of 2000lb car, it will be 700lbs lighter. And, according to this article, using better steel and aluminum or composite materials will not hurt the car's structural integrity with the reduction in weight. And if the car is just as strong and a 35% lighter vehicle crashes into it, then wouldn't that actually be A LOT safer. WOW!
Reply | Report Abuse | Link to thisWhat about dimpling the outside of cars as a golf ball, like Myth Busters showed helped reduce drag? I still haven't seen any cars being marketed this way for efficiency purposes.
Reply | Report Abuse | Link to thisJust 3 thoughts: 1. The people who are saying it will be "just as strong" are members of the industry who are trying to sell their new materials to the auto makers. I'd have felt a lot better if it had been members of the insurance testing institute. 2. A small change to lighter bumpers lead to better gas mileage but gave us astronomical repair bills for 5 mpg crashes. What will these changes mean? 3. Yes, but what if the vehicle that smashes into you is not one the new "whizbang" ligher cars but a 2010 Chevy Suburban? A base course in physics might tell you which vehicle you will want to be in.
Reply | Report Abuse | Link to thisWhat about the VW Golf? :>)
Reply | Report Abuse | Link to thisSorry, I just HAD to do it. (I apologize to all readers.)
Unfortunately, no. The VW Golf did not use dimpling.
Reply | Report Abuse | Link to this"There are literally hundreds of different technologies that can be brought to bear to help improve fuel efficiency, but ALL OF THEM begin with lightweighting," said Kevin Lowery, a spokesman with the aluminum company Alcoa Inc.
Reply | Report Abuse | Link to thisALL OF THEM? Only if you're willfully blind in order to sell a product.
I have an idea. Raise taxes on the giant SUV's and trucks on the road that people don't need and encourage them to buy smaller cars that will be perfectly adequate for their needs.
Reply | Report Abuse | Link to thisLike farmers, ranchers, handymen, delivery folks... and the poor who will be buying the big cars that the rich will put on the used car market after they buy their new, lighter, cars?
Reply | Report Abuse | Link to thisWill we have a federally mandated test to see if a smaller car will be "perfectly adequate for their needs"?
You have a good concept. Raising taxes has been attempted before. Every time the price of gas increases that spike is in essence a tax. Behavior of drivers indicates that the tax isn't high enough to get people to convert to more fuel efficient vehicles. We still observe drivers using the drive through lanes. When we see the drive through lines disappear then we will know we have reached the tipping point for the gas price tax.
Reply | Report Abuse | Link to thisI agree. The ones who get hit the hardest with additional gas taxes are the ones I listed in #11... the ones who mostly have little choice on larger vehicles and often can least afford more taxes.
Reply | Report Abuse | Link to thisI think your point is, correctly, that the folks well off enough to drive the big vehicles as a choice and who may not "need" them (by other people's judgement) are seldom affected by those tax increases and continue to drive big cars/trucks anyway.
It is an extremely complex problem and sound bite style one-liners on either side will not get it done. I applaud real "all of the above" solutions like lightening cars. I just worry about the costs in human lives and additional repair bills (see my bumper example in #6 above) if we only focus on mileage increases.