IIHS studies effectiveness of roof strength: Surprise! It matters
There's been considerable debate between automakers, legislators and safety advocates over how roof strength correlates to deaths in rollover crashes. The majority of the focus has appropriately been heaped on SUVs, whose high center of gravity makes them more prone to rollovers, particularly when they leave the road.
The Insurance Institute for Highway Safety has just released a study that proves that more roof strength can reduce injuries by some 39 to 57 percent when compared to the weaker models it tested. The IIHS used the same roof strength test as the feds on a group of SUVs that currently meet the government's roof requirements. At the top of the heap was the 2000-2004 Nissan Xterra that was able to withstand almost 12,000 pounds of force, while the lowest ranked vehicle, the 1999-2004 Jeep Grand Cherokee, lost its head(room) after 6,500 pounds of force was applied to the roof.
[Source: IIHS]
Reader Comments (Page 1 of 2)
Taylor 5:06PM (3/12/2008)
I'm surprised this was even a debate.
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Kaptain75329 5:21PM (3/12/2008)
Your tax dollars at work. These people need to hold a meeting just to find out if they're going to hold a meeting about when to hold a meeting to discuss whether grapenuts cereal is bag of nuts or a bowl of fruit when the average joe off the street already knows it's neither one in the first place.
Nobody doesn't do it like government.
Julius 5:26PM (3/12/2008)
@ Kaptain,
Umm... IIHS isn't a government agency. This study came out of insurance premiums, instead of tax dollars.
SPG 5:18PM (3/12/2008)
Please, by all means. Make vehicles safer.
Make the roof bars stronger.
However, as vehicles are so frikkin heavy now, use lighter materials.
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Julius 5:31PM (3/12/2008)
Problem is, lighter materials are also more expensive materials (high-strength steel, aluminum, carbon fiber).
And per the studies' own conclusions, "108 of these lives (95 percent confidence interval: 63-148) could have been saved by increasing the minimum SWR required by FMVSS 216 from 1.5 to 2.5. Increasing the minimum SWR to 3.16 could have saved 212 lives (95 percent confidence interval: 130-282)" [IIHS document r1098.pdf, page 11]. Now if we expanded this to the whole country, we'd still be talking about relatively small numbers... perhaps a thousand or so vs. the 43,000 that die a year in the US.
That number isn't small, but begs the question: how much do we spend to save a life?
Nacon 5:28PM (3/12/2008)
idiots... why even bother debate about it when customers can sue them for their lack of safety?
No wonder why they even bothered to debate about global warming and all the hybird ideas is better than 100% electric cars?
GM and Ford are the biggest idiots in the car production world.
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That One Person 2:23AM (3/14/2008)
No. People who can't drive are the biggest idiots in this world. I can't comprehend how people can take an SUV and drive it like it's a sports car.
And then you get those idiots who sue Ford or GM cuz their vehicle flipped 3 times. What cracks me up even more are those people who sue automakers for injuries when the passengers or even the driver didnt even wear their seatbelts.
What the hell do you expect from a two and a half ton vehicle that flips multiple times? Yeah, lets add more weight up top. Smart.
http://www.overlawyered.com/2006/01/rose_marie_munoz_and_the_29mil.html
Hello Moto 5:30PM (3/12/2008)
There shouldn't really be a question as to whether stronger vehicles are safter; the question is if we need to do anything about it. Sure making a roof twice as strong will help prevent it from caving in, but it will also add weight, which removes performance requiring upgrades everywhere in a car to regain its former agility and handling, and all of that weight means you need a stronger roof again. In this article they are implying that we have to make cars safer.
Cars already weight 4,000+ pounds; let’s not keep up this bad design. Light cars use less fuel to do the same thing and are easier on the roads. Are 10, 100, 1000 people a year worth a penalty on everyone else?
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Derek 5:51PM (3/12/2008)
Remove all safety requirements. Test vehicles and require crash results to be posted on the window sticker. Let the public decide how much safety is enough.
Right now our only choices are an armored steel cage with an average weight probably over 4000# or a motorcycle. Please, I want something in between. I am willing to trade some crash safety for reduced weight and increased accident avoidance ability but I do not want to go as far as a motorcycle.
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Tom 5:31PM (3/12/2008)
Nice to see the lowly Nissan Xtera get a little respect.
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phlavor 5:02PM (3/13/2008)
Although I've never had a need for an SUV, I've always liked those Xteras. Glad to know their ruggedness isn't just painted on.
Mehul 5:31PM (3/12/2008)
What about the 4 door wrangler?
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MD Drew 9:50PM (3/12/2008)
They didn't test any Wranglers (interestingly the Liberty made the cut, though; so much for trying to look at real SUVs...)
I would wager that the Wrangler would have the best strength, for several reasons: 1, the roll cage is actually designed to handle a roll. 2, The relative weight is less than some of the others (in the 2 door, especially) and 3, The center stack of the cage is solid, with hefty bolts and welds to the other bars: the body and frame will probably bend first.
Would've been fun to find out how it woud do though...
Guenther 10:42PM (3/12/2008)
Funny you make the distinction that a Liberty is not real SUV, when the Liberty really epitomises what an SUV is.
Stainless 7:49AM (3/13/2008)
Jeep is very careful in their wording.
They don't call it a "roll" cage anymore. In fact, they haven't since the YJ. They tiptoe around and call it a "sport" cage.
I've seen a few OE cages after slow rolls offroad. They usually do hold up ok, but they are nothing to brag about.
I've owned several YJ's in the past and I'm on my 3rd TJ and I've never felt that the OE cage was truely designed with a rollover in mind.
Julius 5:36PM (3/12/2008)
Why is this a GM and Ford problem?
Read the article and you'd find that the '02-'04 Explorer had a HIGHER rating at 10" compression than the XTerra, and the '96-'00 Toyota 4-Runner had a LOWER 2" crush rating than the earlier Explorer.
And no automaker will be free of this standard with an all-electric car. That weight will still impact your range in the city to some degree, much like it impacts fuel economy.
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Julius 5:37PM (3/12/2008)
Above was aimed at Nacon...
Sherief 5:45PM (3/12/2008)
Gee, what a surprise.
What's next? A Study that shows higher torque and power per pound yields quicker acceleration?
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why not the LS2/LS7? 5:59PM (3/12/2008)
This doesn't answer any questions.
Yeah, stronger roofs are tougher to crush. Do they lead to safer vehicles is the question. Making stronger roofs will lead to putting more metal up high in the vehicle, which will lead to higher center of gravity and more rollovers.
A good study would tell us whether adding weight up top helps or hurts overall safety.
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Torrent 6:40PM (3/12/2008)
oo the Xterra looks ugly without the roof rack thingy.
The Ford escape SUCKS at cornering. I would know-I used to own one. I wouldn't have been surprised if someone I knew died trying to make a U-turn in one of those things.
So yeah i was afraid when i manuvered that thing around corners. and I would definitley get on the Manufacturers about making sure the roofs of vehicles are safe. I wouldn't wish this on anyone, but if someone's SUV were to rollover, It'd be great to have a roof strong enough to keep the occupants safe.
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