How Auto Companies Are Making Their Cars Lighter – Wall Street Journal
Troy, Mich.—Hunched over a microscope that magnifies objects 2,000 times, two engineers from a Norwegian-based maker of aluminum specialty parts are studying a roof-rail component they just finished handcrafting for a new automotive customer.
What the engineers see neatly sums up the future of auto manufacturing: a part that is just as strong as the one it is replacing, but at less than half the weight.
The global auto industry is leaving no molecule untouched as it searches for new and different ways to wring weight from its vehicles in the quest to reduce carbon emissions and boost fuel economy.
Stricter emissions and fuel-economy standards in the U.S. and many other parts of the world have auto makers not only using more aluminum but sampling other potential materials, such as magnesium, high-strength steels, carbon fiber, compressed wood and even soy. For every 10 pounds they can squeeze out of their machines, it means about 10 to 15 pounds less of carbon dioxide spewed into the atmosphere each year.
But as with any diet, shedding the pounds is no easy task. New materials can be costly. Some are difficult to work with, and others don’t work at all in the automotive manufacturing process.
Perhaps the biggest challenge is the vehicle itself. Most have grown bigger and heavier. Cars and sport-utility vehicles on U.S. roads have packed on 300 to 500 pounds over the past 20 years.
“Size has definitely been creeping into all the segments for at least the past 10 years,” says Charles Klein, General Motors Co.
’s global chief of CO2 strategy. “A compact car is now almost as big as what a midsize car was 10 years ago. You are also seeing much more content on a vehicle, whether it’s for safety or other features such as a rear camera. That all adds weight.”
The typical compact car has ballooned to almost 3,000 pounds from 2,542 pounds in 1996, according to the industry analysts at Kelley Blue Book. There are exceptions. The subcompact sport-utility vehicle has seen a weight reduction: Since arriving on the streets in 2011, at 3,124 pounds, those vehicles are now down to an average of 3,048 pounds.
Mr. Klein says such numbers show how much further the industry has to go. Those who don’t slim down will have a harder time meeting the new Corporate Average Fuel Economy standards that go into effect in 2025 and require auto makers to increase fuel efficiency by anywhere from 10% to 20%.
Cars of steel
Steel continues to reign as the top material. About 60% of the average vehicle is still built out of steel. Steel makers have also raced to keep in step with the changing times by producing lighter grades of steel and instituting different heating and cooling techniques that can cut the pounds without weakening the metal.
Still, auto makers are spending most of their time tinkering with aluminum, which has all the advantages of steel but is generally 40% lighter. The one drawback: It’s about double the price of steel.
That hasn’t stopped auto makers from turning body parts, door panels, hoods and roofs into aluminum. Ford Motor Co.
took one of the biggest plunges two years ago when it switched the body of its top-selling vehicle, the F-150 pickup truck, to aluminum from steel. That substitution cut about 700 pounds in weight.
Sapa AS, an Oslo-based, aluminum-parts-making joint venture of Orkla AS
A and Hydro ASA, opened a research and development center here where it makes and tests parts for Ford, Tesla Motors Inc.
and other car makers. The Sapa center makes its parts using the so-called extrusion method, which, similar to the way a Play-Doh Fun Factory works, pushes aluminum through molds to make a part.
On the roof
When a reporter recently visited the Sapa center, engineers were inspecting an experimental aluminum roof-rail part that is meant to extend above the doors on a vehicle and is less than half the weight of its steel counterpart.
“The industry has been talking about using different material for years, and now they have no choice,” says Jack Pell, Sapa’s vice president of commercial sales. “You are also seeing a domino effect as the industry educates itself about the different materials.”
One such material is magnesium. The alloy is 75% lighter than steel and 35% lighter than aluminum. It is heated and poured into a die to make a variety of parts. The biggest challenge of using magnesium is cost. While market prices for magnesium and aluminum do vary, in recent years the former has tended to be more expensive.
Liftgate weight loss
Fiat Chrysler Automobiles
NV is using a magnesium skeleton covered by a thin steel shell in its 2017 Pacifica minivan liftgate. The magnesium cut 22 pounds from the liftgate’s weight. It also allowed the auto maker to create pockets within the door itself for the installation of speakers and taillamps. The move eliminated the need for about a half-dozen brackets, reducing costs.
Meanwhile, French-based parts maker Faurecia SA
is in the midst of a multiyear project to replace some of the raw materials it uses to make carbon fiber to reduce costs. Currently, a pound of carbon fiber used in automotive production costs $7.30. The company aims to cut that cost in half to roughly $3.60 a pound.
“If we can find a way to change it so that we can produce it much cheaper, then it might be something the entire industry could use,” says Christophe Aufrère, Faurecia’s chief technology officer.
About 90% of carbon fiber is made up of the chemical compound polyacrylonitrile, which also drives the cost. Faurecia is attempting to substitute that compound, also known as PAN, with wood lignin or cellulose. Lignin is an organic substance that binds the cells and fibers of a plant to basically form wood. The substance is readily available and much cheaper to produce than PAN.
Mr. Aufrère hopes that the company will have a solution for mass production ready by 2022.
Mr. Bennett is a Wall Street Journal reporter in Detroit. Email email@example.com.