The Lightweight Car Debate: From Steel to Space-Age Materials
Decades ago, cars were almost always made from steel, and as consumers we were fine with that for various reasons. Gas was incredibly inexpensive, so we didn’t care how much our cars weighed. Steel quarter panels and chrome bumpers stood for safety, and since no one wore seat belts back then, the attitude was “safety first, the more steel the better.” Back on the manufacturing side of things, automakers were just working with what they had, and that primarily consisted of using inexpensive, heavyweight metal, and lots of it.
But over the years things began to change, and new technological advancements brought us composite materials that had previously been reserved for aerospace usage or were deemed too expensive for commuter cars. Today, cars are made out of everything from fiber-reinforced plastics and military-grade aluminum, to titanium and carbon kevlar, with new materials popping up on the scene all the time.
We recently covered Ford’s invested interest in the use of carbon fiber, which illustrates some of the reasons why auto makers are making cars as lightweight as possible. We all know that lighter cars typically get better fuel economy, but what many Americans may not know is that the U.S. government has mandated that all auto makers must have fleets that average 54.5 miles per gallon by the year 2025. So the featherweight race is on to see who is going to make the cut and who is going to get left behind.
When dealing with something as complex and heavily regulated as automobile manufacturing, setbacks can be both enormous and expensive. While cars may not be made entirely out of metal like they once were, it’s interesting to see that they have indeed gotten heavier over the years; a recent piece we did on vehicle weight highlights some of the pros and cons of driving lighter and heavier vehicles. This increase in weight is primarily due to government required safety equipment, heavy technological enhancements like infotainment systems, and bulky performance-oriented components like all-wheel-drive systems.
A study by Scientific American shows that “trimming a car’s weight by one-tenth can boost fuel economy by 6–8%” and that a team of scientists in South Korea has invented a form of steel that is lighter and stronger than titanium, but is still easy to work with because it’s steel. Developments of this nature carry with them a lot of potential for shaving unwanted weight, and in Korea, it is reported that steel production for its car industry “has grown nearly 50% since 2005.”
What are the downsides to making cars more lightweight? There is the sheer cost of manufacturing a car out of materials like carbon and magnesium, which are notoriously expensive to refine and mold on a large scale. There also is the issue with sourcing substances like carbon and titanium in massive quantities, as reliable suppliers for these space-age components are as limited as the materials themselves. Once the car is completed what then? Automakers are going to have to pass on some of these added expenses to the consumer, and it is highly doubtful that someone is going to be willing to pay thousands more for a lighter Ford Fiesta.
Another issue that people fail to consider is what it costs to repair a vehicle that is made out of race-spec materials. Where new metal fenders might set you back a few hundred dollars, carbon fenders typically cost more than double that of traditional metal panels. Stability is another issue people are concerned with, since strong wind gusts while driving down the freeway can spell disaster for a car that weighs next to nothing.
We stand at an interesting automotive crossroad, and only time will tell which path auto makers will take. Before us lies a trail littered with lightweight materials that are both strong and expensive, no longer reserved for Formula 1 cars alone. Behind us are steel stamped car components and welded chunks of chassis, rusting away with inexpensive iron block engines. And on either side of us are the current directions the auto industry is traversing, where steel, aluminum, plastic, and carbon are blended together to make the common car. But with increasing pressure from world governments and advancements in refining and construction, there is a strong chance that the way forward contains futuristic lightweight components and one day we will see commuter cars being made out of these materials.
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