Will Introducing More Plastic in Cars “Green” the Fleet and Enhance Safety?

Dupont’s CEO Ellen Kullman says “We make high-temperature plastics. Your powertrain in your car has an amazing amount of plastics in it. When I really took a look at where plastics have gone over the last few years, it’s amazing. If you can save a couple hundred pounds on a car, you can get one point of fuel economy.”   If  plastic cars are lighter then vehicle fatalities decline and unless you believe in a big rebound effect then improvements in MPG will translate into less greenhouse gas emissions.  Was the guy from The Graduate right about the future of plastic?   Could more plastic be a key to improving our quality of life?

Author: Matthew E. Kahn

Professor of Economics at UCLA.

14 thoughts on “Will Introducing More Plastic in Cars “Green” the Fleet and Enhance Safety?”

  1. Absolutely! As the Romney campaign illustrates, you can make virtually anything out of plastic these days.

  2. Well-it’s not just the rebound effect that makes plastics less efficient than their face effect. It’s also the effects on durability and repairability; if a car/appliance whatever costs less to make and operate (in carbon terms, not cash terms), but needs to be replaced sooner, the net gains are lower by the increase in number of items needed.

    This effect is observable when you look at how much less of a collision it takes to junk a 1990’s car than a 1960’s car.

  3. “This effect is observable when you look at how much less of a collision it takes to junk a 1990′s car than a 1960′s car.”

    That’s not due to their being built out of plastic. It’s due to the combination of safety standards and CAFE. In order for a small, light car to be safe, it must absorb energy in a collision. The way it does this is by getting broken. “Crumple zones” and the like.

    It’s perfectly possible to build safe, durable cars, out of metal or plastic, but they won’t be high mileage.

  4. Serious economic question. Why is the damage which your car causes to others an unpriced externality — shouldn’t this be fully internalized via insurance prices? If not, why not?

  5. SamChevre: it’s not really fair to blame lack of repairability on plastics. A major reason it takes so much less of a collision to junk a modern car is that the metal structural components (which is most of the car, hence unibody) are designed to absorb energy by deforming irreversiblly in an accident. That saves lives compared to the 60s car. There’s also the matter of the ever-higher cost of repairing cosmetic damage (in part because factory finishes get more and more sophisticated and harder to emulate, in part because insurance coverage allows it) but no one ever junked a car because of that.

    The downside, rather, is that structural plastics (for the most part, currently) don’t recycle worth a damn, whereas scrap steel (with some qualifications for some high-strength alloys) not only recycles indefinitely but is a crucial ingredient in the making of new steel. (High-temperature plastics are pretty darn revolutionary, but as long as cars use internal combustion there will still be way too much metal.)

  6. “This effect is observable when you look at how much less of a collision it takes to junk a 1990′s car than a 1960′s car.”
    If the fraction of cars that is junked because of collisions were a LARGE fraction of the cars that were junked, this might be a relevant argument.

    A more relevant issue is the fact that better engines have been squandered in creating heavier cars, not more efficient cars. Sure, plastics COULD be used to create more efficient cars. They could also be used to create cars that are gratuitously inefficient (eg because their shape is striking, and sells well, but is not at all streamlined).
    To argue that
    – plastics now exist that can replace heavier components in cars
    – therefore, la la la, cars will become more efficient
    displays an astonishing ignorance of the history of the auto industry.

  7. “That’s not due to their being built out of plastic. It’s due to the combination of safety standards and CAFE. In order for a small, light car to be safe, it must absorb energy in a collision. The way it does this is by getting broken. “Crumple zones” and the like.

    It’s perfectly possible to build safe, durable cars, out of metal or plastic, but they won’t be high mileage.”

    you don’t understand how things are designed and made. Its cheaper to replace than repair – repairs require application of skill to a single item without the scale of new manufactures. The better (more advanced, complex, embodying upstream technology) something is, the more disposable it becomes.

    But I agree with you, that we should credit regulations restriction businesses for one of the biggest improvements to human non-death.

  8. Now that gas fuel prices in USA are aproaching those enjoyed by europe fuel economy will start to become a real selling point. Wouldn’t have been cheaper and more effective to do it by regulation than economic force. If only we had listened to that awful Jimmy Carter, instead of that nice man Ronald Reagan we would likely be fuel independant by now and could have avoided a couple of unnecessary wars and so our economy wouldn’t be in the toilet. But that Carter guy was so nerdey with his sweaters and all.
    So yeah, with $4 a gallon gas plastic parts will help bring american autos up to the standards they should have been twenty years ago. Invisible hand and all that.

  9. There are small MPG gains to be made from using less steel and more plastic, but the big gains are simply switching to smaller cars with smaller engines.

    Since the public is too greedy and short-sighted to support the high gas taxes every other civilized country in the world has, we Americans will just have to wait another 2 or 3 years for high oil prices to make us switch over to small efficient hatchbacks for most travel.

  10. I wish that serious bloggers wouldn’t mention the rebound effect: i.e., any attempt to do something ends up encouraging the opposite. I admit that it is sometimes real. No insurer would insure a shack for a billion dollars. But it is generally nonsense. The life insurance industry does not create a high suicide rate, although it pays for suicide if committed two years after taking out the policy.

    Although occasionally true, the rebound effect is standard right-wing cant: up-is-downism. Look at the way it is used. The proponents of the rebound effect never seem to think that it applies to corporate profit-seeking, for example.

  11. It takes a lot more fossil fuel to make a ton of steel than it does to make a ton of plastic.

  12. The solution to all of the above is a national 35 mph speed limit. If cars only had to be built to withstand crashes at 35 rather than 75 or higher, they’d be tons lighter, cheaper, and consume far fewer resources over a lifetime of service, which would be greatly enhanced. If you want to go faster, get on a train or fly.

  13. Ebeneezer:
    Although occasionally true, the rebound effect is standard right-wing cant: up-is-downism. Look at the way it is used. The proponents of the rebound effect never seem to think that it applies to corporate profit-seeking, for example.

    There’s a paper or book pointing out that the right has frequently relied on three arguments for centuries – futility, perversity and [can’t recall the third thing]. It’s pretty much a fill-ing-the-blanks argument.

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