Posted on 05/23/2009 5:09:48 AM PDT by ovrtaxt
President Obama announced on May 19, 2009, a “historic agreement to help America break its addiction to oil.” The centerpiece of that announcement was a new 35.5-mpg CAFE standard for 2016. Rocky Mountain Institute (RMI) has been advocating the entry of fuel-efficient cars into the market for years. The time is now ripe, and we are in the midst of a major national push for the adoption of these cars.
One of the barriers to widespread adoption is the common-yet-misleading line of logic that most consumers follow—that fuel efficiency equates to smaller, less safe cars.
This misperception is fed by the media, including an April 14 New York Times story, “Study Says Small-Car Buyers Sacrifice Safety for Economy” and a May 22 The Wall Street Journal piece, titled “Light Cars are Dangerous Cars.”
Sure, based purely upon a typical vehicle's design, geometry, and occupant position, we agree that larger—but not necessarily heavier—vehicles can offer considerable safety advantages to passengers within. But left out of this quickly developing story is engineering design.
Recent research by Rocky Mountain Institute indicates that an ultralight vehicle that is large and better designed can have crash safety comparable to, or better than, that of a similarly sized heavy vehicle. The platform of a light and large vehicle relies on stronger, lighter materials. Designing for passive safety on par with current NHTSA five-star ratings demands not only using lightweight materials, but also new vehicle geometries and components that can act as energy-absorbing crumple zones. Indeed, a lighter vehicle can achieve the performance of a conventionally designed vehicle, but because it can do so with a smaller engine, there is more room in the engine compartment for crush space and, ultimately, a better crumple zone design. Furthermore, automobile manufacturers are beginning to incorporate advanced active safety features, such as side curtain airbags, and collision prevention systems, such as Volvo's "City Safety."
There is another aspect of safety not considered when using conventional logic: the safety of the people outside the car. A lightweight vehicle will be less aggressive (less likely to injure the occupants of another vehicle, bicyclists, or pedestrians external to the primary vehicle in a collision), thereby reducing the overall number of traffic deaths. For an object moving at a given speed, a reduction in mass corresponds to a reduction in the amount of energy that object brings into a collision with another object. Thus, a lightweight fleet (traveling at the same speeds) is statistically less dangerous than a conventional (heavy) fleet.
As part of our research on vehicle lightweighting, RMI reviewed all the available data and commentary about the relationship between size, safety, and weight, including reports published by the National Academy of Sciences and the National Highway Traffic and Safety Administration, and the Insurance Institute for Highway Safety (IIHS). Many reports link size and weight as being responsible for safety reductions, while the most recent studies disaggregate the two, and find size alone to blame.
In a January 2007 article, IIHS stated “a way to improve fuel economy and maintain vehicle crashworthiness is to use lighter materials that reduce vehicle weight but not size.” IIHS also noted “Indexing these requirements to the vehicle size makes it less likely that auto manufacturers will reduce the weights of their vehicles in ways that degrade occupant protection, and some weight reduction, especially among very heavy vehicles, could improve total safety by lowering the risk to other people on the road.”
The fact is that today, there are not many examples of vehicles that have been designed to be both lightweight and large. This will soon change as domestic and overseas automakers explore designs and materials that will be both fuel-efficient and safe.
RMI continues to encourage OEMs to make efficient, lightweight cars. We hate to see the benefit that comes from fuel efficiency thwarted by misconceptions about safety trade-offs. Both fuel efficiency and safety can be achieved and both are good for the health of the country in more ways than just safety on the road.
Results of a recent RMI study on this topic are expected to be released in July.
For additional information, please visit www.rmi.org.
The authors are all employees of Rocky Mountain Institute, where Mike Simpson is a transportation analyst, Kristine Chan-Lizardo is Interim Director of the Mobility and Vehicle Efficiency Team (MOVE), Cory Lowe is a public relations manager, and Cameron M. Burns is Senior Editor.
They GAVE AWAY FOR FREE the technology that led to the Prius. Toyota took them seriously, the rest did not.
They have great ideas that more car companies should be listening to.
ping
Expense no object.
Race cars use the ultra lightweight materials, but they're far too expensive for production cars. Nobody could pay the freight.
If extreme fuel economy is mandated, we'll just get shoeboxes on roller skates and the consequent increased fatality rate. And Zero and his minions will continue to ride around in armored limos, so what do they care?
Economies of scale. Once you start cranking out thousands upon thousands of these things the price drops.
Correct me if I’m wrong here, but the gist of the article seems to indicate that lighter is not less safe, but smaller is.
So a large but light and fuel-efficient auto doesn’t compromise safety.
If this is truly what they are saying, I don’t think this is a big revelation. I also think it doesn’t invalidate those who criticize Obama’s proposal on fuel standards. The solutions that will be proposed will inevitably be smaller cars, not lighter, big cars.
People can clearly understand that a Smart Fortwo isn’t very safe in a collision with a Tahoe, but a lighter Tahoe won’t necessarily compromise safety vs a heavier Tahoe.
I don’t see how the article is ground-breaking.
Am I missing something?
Lightweight cars will be safe after 0bama mandates everyone drive one. They’ll be the only car on the road.
Yeah, they are just as safe as larger cars ... until they get into an accident.
“The time is now ripe, and we are in the midst of a major national push for the adoption of these cars.”
If the time is ripe then we don’t need the government forcing auto makers and consumers to “adopt” these cars, the market would take care of it. Any time the government decides things that the market is best equipped to handle everyone pays a huge price. The auto makers will have to make cars the consumers may not want and the consumers may have to buy cars they don’t want. Our problem isn’t a lack of oil, our problem is a prohibition against drilling for it. The government outlaws drilling which forces us to import more oil, then to solve that problem they force us to drive smaller cars. What’s next when this doesn’t work, forcing us to ride motor scooters?
You are still looking at far more expense for lightweight materials, as opposed to good ol' fashioned steel.
Which explains why one word was missing from the article.....a word that only a military subcontractor would rarely use in their world.
What is that word?
COST
It is cheaper to build a small, vunerable car to meet CAFE standards than to use exotic materials and build a lightweight, safer car to meet CAFE standards.
But like most people who want to make a point by ignoring the elephant in the room, this author ignores cost as a factor.
Do a search on the article. The word "cost" is nowhere to be found.
Even the lightest trucks are 2 + TONS. Will Ra'am Ahmanuel and his puppet ban all trucks/tractor trailers from the roads?
And, I suppose the electric (plug-ins) cars will only use the electricity produced by the non-polluting coal & oil. Sheesh.
Nope, that’s pretty much it. The mass of the vehicle is the critical element, not a smaller size in terms of dimension. Using composites for structural elements rather than steel makes all the difference. You can then scale down the engine. Adding advanced energy management systems (like the brakes on the Prius) allows a further reduction in engine size.
It’s not incredibly earth shattering, but why isn’t anybody doing it on a mass scale?
This is why old, crusty companies need to be allowed to fail, and newer, more agile players need to enter the market. WITHOUT GOVERNMENT INVOLVEMENT.
Really this can't be mandated because the market will not be able to catch up.
If this were practical and cost-effective, the market would respond. It hasn't, ergo . . . .
There is another aspect of safety not considered when using conventional logic: the safety of the people outside the car.
This is all well and good if the vehicle hits another vehicle or object, but It won't get you through a snowdrift. That takes momentum, a function of mass. I have seen quite a few vehicles this spring with front end damage (which amounts to expensive broken plastic) from last winter--just from getting through snowdrifts on the highway. Lighter vehicles seem more prone to being deflected from their intended course by snowdrifts as well.
Now before you say, "So what?", here it is 120-130 miles between major towns along the main roads, winter temps are commonly below zero, and cell phone service, while slowly improving, is far from universal. In short, a trip to the ditch, especially one which disables your engine (and thus, your heater) can be a death sentence.
While this may be appropriate for warmer latitudes, I don't consider anything 'efficient' if it can't be counted on to get you there and back.
Certainly smaller vehicles tend to be more maneuverable and handle better than the largest ones. That makes it easier to avoid the accident in the first place and makes you less vulnerable to single car crashes.
As far as light but large, in a head-on you are going to be pushed back the way you came. A Smart car and an SUV head-on at 50 will see the Smart's velocity change by more than 50 (maybe +50 to -20 for a change of -70) while the SUV's changes less than 50. Which would you rather be in?
Shorter and/or lighter both kill.
Do a search on rmi.org. They do not ignore cost.
I might seem like a cheerleader for them, but I honestly like this organization. They have genuinely good solutions.
Yep.
In my neighborhood, the state is considering lightrail to run 150 miles to the Twin Cities area. Problem is, the Great Northern (now Burlington Northern Sante Fe) stopped this run in the 1960s because it was unprofitable. Now tax dollars will go to fund it. But, guess what? There is a mega-casino located exactly half way on the rail line.
Follow the money.
Oh, the market is responding. Have you seen the sales figures for the industry as a whole?
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