Sorry Detroit, Heavy Cars Are Not Safer
by Andrew Posner, Providence, Rhode Island on 02. 5.08
A while back we covered the Competitive Enterprise Institute's claim that the new CAFE standards will cost lives due to lighter and, in their opinion, more unsafe cars. That led to some animated discussion--as well as some confusion--as to whether or not the weight of a vehicle determines how well it performs in a crash. Well, according to Laura Schewel, an analyst with MOVE, and Noah Buhayar, a fellow at the Rocky Mountain Institute, such confusion is common:
Many consumers believe that the goals of a "safer car" and a "more fuel-efficient car" are at loggerheads, and that any increase in gas mileage will lead directly to increased fatalities.This misconception is based in large part on a common assumption: The heavier the car, the safer it must be. Collectively, Americans have bought into this idea. The mass of the average personal vehicle in the U.S. has gone up 29% since 1987.
So what, in fact, makes a car safe?
Clearly, there is a tendency to associate weight with safety. After all, having a massive cage of steel surrounding a driver is comforting, but it turns out that " the best scientific research shows that automotive safety has nothing to do with vehicle weight, but everything to do with vehicle size and design." This is because vehicles do not "collide like billiard balls on a table; they have crush zones and structural features designed to absorb impact." As a result, the surface area available (either thanks to a long or wide design) is what determines the extent to which the vehicle can absorb the impact.
Based on those facts, a heavy car can be safe, provided that it is well designed. However, heavy cars are also worse when it comes to crash avoidance. And then there is the issue of fuel efficiency, which is directly related to, among other things, the overall weight of the vehicle.
None of this should be too surprising. Automakers, such as Nissan, are actively working to lighten their cars. Meanwhile, start-ups such as Aptera are looking to revolutionize vehicle efficiency with their ultra-lightweight designs. And "studies have proven that increasing the length of a car (its crush zone) while maintaining the same weight leads to reduced fatalities."
Sorry Detroit: it turns out those heavy cars you've been making all these years aren't any safer after all.
Via: ::Yahoo! Green
See Also: ::"CO2: We Call it Life" ads: We Call it Hysterical, ::China, Russia and Cuba Seem to Agree With the Competitive Enterprise Institute, ::Huffington Post Gets Astroturfed, ::DaimlerChrysler's Bionic 70 mpg Car and ::GM Keeps its Greener Cars Out of North America
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My Honda Fit weighs in at only 2600 lbs., has 6 airbags, phenomenal crash test ratings by both the government and the IIHS, and gets near 40 mpg highway to boot.
Let's not forget the issue of "size". The larger the car, the heavier it is. Size significantly increases the risk of collision because there is just more surface that can cause "impact". I am surprised that this issue is never raised. Larger (heavier) cars also take much longer to stop thereby increasing the risk of rear impact.
"Sorry Detroit: it turns out those heavy cars you've been making all these years aren't any safer after all."
Sorry Andrew, many of them are. As your article points out size matters, and the heavier vehicles are also larger. The top ten lists vary based on criteria, but all are consistently dominated by large vehicles.
Example 1:
Acura RL
Volvo S80
Honda Odyssey
Acura TL
Chrysler 300C/Dodge Charger
Lincoln Town Car
Buick Lucerne
Lexus ES 330
Lincoln LS
Honda Pilot
Example 2:
1 2008 Ford Taurus
2 2008 Jeep Commander
3 2008 Jeep Grand Cherokee
4 2008 Lincoln Town Car
5 2008 Infiniti FX
6 2008 Honda Pilot
7 2008 Mercury Sable
8 2008 Mercury Grand Marquis
9 2008 Chrysler Town & Country
10 2008 Toyota Highlander
SUV's lose points due to their tendency to roll over, but still IIHS's top picks(http://www.iihs.org/ratings/default.aspx) includes 19 "SUV's", but only one "small car" (and it is all wheel drive).
Part of the reason big cars, particularly SUVs are "safer" is because they dramatically increase the odds of killing the driver of the car they hit. I can accomplish the same "safety" by putting big spikes all around the front end of my car.
The idea that heavy cars are inherently "safer" is at odds with reality not only because of the design of cars, but because of the meaning of "safety." I will bet you money that when people say "safe" in this context, they are talking about the safety of the people inside the car. But what about those outside the car, on the street? Or what about those in smaller, lighter cars?
What does safety really mean? The context of the word makes all the difference.
Ross: You are asking: "What does safety really mean? The context of the word makes all the difference."
..
It is the safety as in 'National Security', an common Nord American way of think:
Security to us. F.. the rest!
Sorry, but the world is looking at you!
You are the most stupid people of the world, and people are stupid anyhow.
You can call me an idiot or you can think about!
Best regards
Honda/Acura invented the ACE body structure.
They use different types of steel to direct the crash energy away from the passenger/s. Honda invests more money than any other car company into R and D.
How safe are busses for the occupants of the bus and all around them?
Boy good thing that it is only the evil men of Detroit that bought in to the heavier is better. Luckily Toyota doesn't make anything heavy like the FJ, the Sequoia, The 4-runner, the Land Cruiser. Thankfully Nissan doesn't make anything heavy like the Titan, the Xterra, the Pathfinder, the Armada.
If you want to bash the auto industry, at least be fair about it. While Toyota seems to get all the praise and GM all the flak here on TH, remeber that the Toyota FJ cruiser, the Japanese Hummer wannabe, is selling so fast that Toyota doesn't even bother to advertise it.
Anyhow, weight isn't the only factor in safety. Anybody over simplifying to that extreme it is just doing to to make themselves sound knowledgable. Physics is a lot more complicated than that.
-Lego
This argument is silly. The consumers are arguing about accidents between big car vs. small car. The industry is arguing car versus block of cement. To add to that, speed has as much to do with it as size. Remember that little equation: e=(mc)squared? If the public wants safety, they ought to slow down. But that's like taking away their TV.
CEI didn't need to make any claims about vehicle safety, it only needed to promote the findings of the National Academy of Sciences, which is exactly what CEI did.
According to a 2002 NAS study of CAFE, downsizing contributes to about 2,000 deaths per year.
These findings have not been challenged in any real way by TreeHugger, they've only been found guilty of association with CEI, which isn't a real argument.
You can dismiss arguments you disagree with because you don't like who's making them all you want, but that doesn't make the data false.
Did someone throw physics out the window? Of course the design of a vehicle effects the safety. Assuming both are done with good designs, I'd rather be in the heavier vehicle. Would you put your infant in the Smart? And of course automakers are making cars lighter. They all are. It will be required to meet the new CAFE.
I see, the smaller, the less crush damage. So smaller people should be playing football, right? "Smart" baby buggies will save you in a head on collision but you're doomed in your pickup truck. Please. Go peddle that misinformation somewhere else! Flash, we're doomed,, the polar ice cap will melt in two weeks if we all don't buy horses. News at 11.
Vehicles are a LIFESTYLE.... I can't drive a small car... I would NEVER be able to haul, carry and doo the things I do, without a truck...PERIOD!
I'm no expert, but it seems to me that weight has nothing to do with safety: a typical F1 race car has a fraction of the weight of an SUV yet it is much safer. It's all about the design and the way the car is designed to crush in an impact.
Pathfinder, I want you to consider your statement. I don't need a big truck because I have a 4x8 trailer that I can pull behind my Malibu. The trailer was cheap ($200 at a yard sale), and only impacts my fuel economy when I'm pulling it. Consider if you could get by with a small trailer instead of driving a truck around.
Buy what you like....I will put my wife and kids in a nice, larger, safe vehicle. Crumple zones and special steel are great, I am going big for my family's safety.
@Einstein
No offence, but you should really review your physics.
A heavy vehicle at 100km/h does have a lot more energy to absord than a light vehicle (because of the cinetic energy).
So if two vehicles with the same design (same compression zones and reinforcement bars) crash against a wall or a pillar or a tree or a rock (and so on), believe me that the heavier vehicule will be a lot more damaged than the lighter one.
That is physics !
But, and this is maybe why people still prefer heavy vehicles, if two vehicles with the same design crashed against each other, the heavier one will be less "shaken" than the ligher one (again, because it's cinetic energy is higher than the other one, so the heavier vehicule is "powerfull" than the ligher one).
About the smart : The smart is a very very safe vehicle, DaimlerChrysler's engineers did a great job there. You can watch a crash test at 90km/h against a wall on youtube : http://www.youtube.com/watch?v=ju6t-yyoU8s .
@AL : You're completely right about F1, this should convince everyone here. you can survive at a 300km/h crash on a F1. The F1 wheight only 600kg and have a great design (the big noze of the car is a wonderfull compression zone) and is made in very light and strong materials (like carbon)
To conclude, I would say that the bigger issue about SUV is that their bumpers are way too high and it's really dangerous for other efficient cars or pedestrians (if you're hit by a "small" car, a part of the energy of the heat is absorbed by the bonnet and the windshield which are quite flexible, as you can guess, since the bumpers of a SUV or a 4x4 is a lot higher, the pedestrian suffer a lolt more with a SUV).
One issue that is consistently overlooked is that of personal injury litigation. When we had the last gas crisis back in the 70s, many car makers made their vehicles lighter. No one in the industry thought this made the cars less safe, but plaintiffs' attorneys were able to convince juries that the car makers put the market's demand for fuel economy ahead of occupant safety. It was a completely bogus argument, but it worked on juries because Americans believe heavy = safer. Something needs to be done to permit car makers to build lighter cars without risking this type of liability.
"a typical F1 race car has a fraction of the weight of an SUV yet it is much safer"
-An F1 car is built specific to the size of the driver, and the seat is molded to the driver's body. A street car has to be able to accomodate drivers and passengers of a variety of sizes.
-An F1 car is quite difficult to enter and exit, has almost no visibility to the sides and none to the rear, and are said to be quite uncomfortable. A street car is designed for ease of use, visibilty all around, and comfort.
-An F1 driver wears a 5 point harness, HANS device, and custom made helmet. Street cars have three point harnesses, and I've never met anyone that is willing to wear a helmet or HANS device during their commute.
-An F1 car is constructed of carbon fiber and costs up to 100 times as much as a street car.
-F1 cars only run on tracks constructed to FIA specifications, so they never collide with anything uncontrolled. Street cars have to deal with all sorts of road conditions and hard objects.
-F1 cars are all the same size and all run in the same direction, so they never hit any vehicle heavier or at a speed greater than their own. Street cars are all different sizes and run in opposite directions, so it is possible to have a collision with a vehicle of greater mass with a speed differential of twice your own.
F1 cars are safer but also expensive and impractical and only under controlled conditions. On the street an F1 car would easily be crushed under a larger vehicle or shattered by a collision with a concrete structure, tree or pole.
One last point...
-F1 cars are driven by the most skilled drivers in the world. Street cars are often driven by idiots.
If drop my two wrist watches - a '80 plastic Swatch and a heavy steel cased Seiko divers watch - from shoulders height on to a concrete pavement. Now, which watch would suffer the fall the least?
According to Newton, the watches will pick up speed at almost exactly the same pace, they will hit the concrete sidewalk with equal speed. Air resistance is of no importance here.
Due to the fact that I would have to apply more power to lift the Seiko, its kinetic energy will be equally higher - therefore this watch will hit the ground with greater force.
The fact that a heavy steel construction is rigid to a blow means that the material will give little away on impact. Because of this, all parts that are more or less loosely fitted inside the steel frame will be all the more subject to the forces at stake.
Off course, the Seiko will run the biggest risk of being destroyed on impact.
In Europe, we find the US attraction for SUVs and huge pick-ups a bit strange. There are obvious cultural differences here, but safety is NOT the issue here. If "bigger is safer" were true, then there should be substantially lower rates of fatal traffic accidents in the US compared to Europe. In fact, it is the other way around - while e.g. Sweden recorded the lowest number of fatal accidents since the 1940's in 2005, in USA the same year fatalities reached the highest number in 15 years. This is difference can off course not be reduced to a matter of vehicle sizes, but is well worth taken into account, considering the fact that, as the article above states, the mass of the average personal vehicle in the U.S. has gone up by 29%since 1987 - a trend unsurpassed elsewhere in the world. Sam-Hec points out that the Japanese also produce large-size vehicles, but many of these are zoned for the US market - in fact some models are almost not obtainable outside USA, not even domestically where they’ve been produced.
I find some of the remarks above utterly idiotic and uneducated. There are off course some very few situations where a big bulky car will be the safest to drive. Other times, the safest thing in the world might be tailgating the suicidal driver of a load of nuclear waste, with both hands wavin' free. Still, it will never be safer to be on the receiving end off a runaway Hummer than a small Audi, what ever pants you may be wearing. If I'll ever lose control over a car on a freeway, I pray to Newton that I am not driving a SUV or large pick-up.
The big point that the big-car-defenders seem to miss, is that a general reduction in the mass/weight of new car models will make the general traffic environment safer. In accidents where two or more vehicles are involved, a lower total mass of the vehicles will reduce the risk of fatal injury. If I place my Swatch on the pavement and drop my other watch on it, it had best been another Swatch, right?
Arguing against this is like saying: Hey, cars don't kill people, people kill people. I guess you've all heard similar arguments before.. For some strange reason, this is generally not how we deduce in Europe. Perhaps damage control isn't a big virtue in the US.
I haven't even mentioned the global warming issues related to the fuel consumption of large vs. small vehicles - but then again you don't vote for politicians that are particularly interested in dealing with global issues, unless it can be done by dropping at least a few bombs;)
all you guys are idiots. tell you what lets do you get in your overated honda and i will get in my 1982 dodge heavy duty club cab 5700 lbs. and we both go 60 mph. and crash head on and we will see who goes to the hospital.
Anytime I buy a new car the first thing I think about in me and my families personal safety. I do my homework on crash ratings. I never took the weight of my car into account, alway looked for how the car was built and how structurally it was designed to protect me.