220S

Volvo engineered the front wheel mounts (starting back in 1993 with the 850) to break away from the body in a severe impact to prevent the wheel from intruding into the cabin.

WEBSRFR

What I'd like to ask from Mercedes is why they did not design the side impact airbags to deploy in such a massive frontal collision. The top rated cars in this test, both the Volvo and the Acura deployed the side airbags and it protected the driver.

It is arrogant and idiotic of Mercedes to not program the side airbags to protect the driver in such a situation and claim there is nothing wrong with their safety systems. The facts show otherwise. Just look at the enclosed photos below:

IIHS Excerpt - About how the Acura side airbags worked to help reduce injury: Restraints/dummy kinematics — The dummy’s movement was well controlled. The dummy’s head loaded the frontal airbag, which stayed in front of the dummy until rebound. In both tests, the side curtain airbag deployed and had sufficient forward coverage to protect the head from contact with side structure and outside objects. The side torso airbag also deployed in both tests, protecting the chest from potential contact with side structure.

IIHS Excerpt - About how the Volvo side airbags worked but could have been better designed to reduce injury: Restraints/dummy kinematics — The dummy’s head contacted the frontal airbag but slid left into a gap in coverage between the frontal and side curtain airbags, leaving the head vulnerable to contact with forward side structure and outside objects, despite good stability of the steering column. This gap is mainly due to a combination of the narrow, asymmetric frontal airbag and a curtain airbag that doesn't extend sufficiently forward. The side torso airbag also deployed, but too late during the crash to protect the chest from potential contact with side structure.

It is a fact that side airbags help in a situation like this. If you need more proof, look at the contact areas of the side-air bag during the crash. I think most people would much rather be cushioned by an air bag in this situation rather than make contact with the side structure including the B pillar or the window glass. You don't even need to make contact with the side structure as your eyes can be severely injured by glass fragments from the side window absent any protection from the deployment of the side airbag.

Look how well the driver's head is protected in the Acura:


Unfortunately in the Mercedes, the driver's head makes contact with the deformed A pillar and side structure absent any side protection:



IIHS Excerpt - Mercedes crash test: Restraints/dummy kinematics — The dummy’s head remained in contact with the frontal airbag, but its head still moved toward the intruding A-pillar because the seat belt allowed excessive forward excursion of the dummy's head and torso. Neither the side curtain nor the side torso airbags deployed, leaving the dummy's head and chest vulnerable to contact with side structure and outside objects.

When you bought the car, you also paid for the air bags. What is Mercedes doing "Saving" the airbags in a collision that is likely going to total the car anyway? I think they should issue an immediate recall to reprogram the airbags to inflate in a massive collision like this the way Acura and Volvo has done.

WEBSRFR

While they are at it with the fancy wipers, they should kindly turn on the side airbags in a massive collision that may breach the integrity of the safety cage

220S

In the IIHS report, they did mention this: Additionally, Mercedes has already planned to modify the current C-Class airbags. I don't know what that exactly means however. Did they know this was an issue before the IIHS testing?

imho, the worst thing about this is Mercedes' attitude. It was incredibly arrogant and they lose a lot more points with that then any test results. It's like when Porsche flatly denied that there was an IMS issue with their motors back in the late 1990's. They played the old 'we know better than anybody else' game.

Acura has stated that for the TSX (which was 'marginal' in the test) they will investigate the side airbag deployment. Apparently the IIHS had to do two tests with the TSX since the cameras weren't operating properly in the first test. The side airbags deployed in the first test but in not the second. Acura said they need to look at the 'detonation threshold' and fix it if it is indeed an issue.

Mercedes could have come out and said something to the effect of "we will look into this" or "we would like to spend more time considering the results of the test" etc.. Instead it seems all they could think of was the bottom line: sales.

bhamg

IIRC in the 2010 C-Class models MB added a lower-dash airbag, presumably to better protect the lower leg. That would suggest their own testing revealed some weaknesses in the original configuration not related to head injuries.

otakki

+1

Meanwhile, maybe I should wear a helmet while driving until all these get sorted out.

K-A

Apparently M-B did put out this statement as well:

Dirk Ockel, head of accident research at Mercedes-Benz: "When two cars collide they tend to hook themselves into each other. If you had put on the corner of a deformable obstacle corner, the results would probably be more realistic. Of course we will deal with this test because either way, customers are confused by the results." Translated from Spiegel Online/MB Passion

bhamg

Kind of a unfathomably stupid statement from MB IMO. How more realistic? They tested for vehicle-on-rigid object collisions, not vehicle-on-deformable-object collisions (i.e., car-on-car). Both types of testing are valid. No confusion whatsoever.

220S

Exactly. It's just more 'we know better than the consumer' double-talk.

Nobody's confused. And the fact remains that Volvo did their in-house testing of small offset frontal accidents using two cars and not vehicle-on-rigid collisions. They concluded that it's important to build a steel crossbar that connects the frame to the firewall/pillar area in addition to having the front wheel mount break loose. And to have the side curtains deploy.

K-A

To M-B's defense, they have decades of real world crash data that signifies that they know safety better than most. Since the IIHS started gauging fatality rates, M-B's have proven to be the most life saving in real world collisions. When it comes to crash testing, as we see with the "Moderate Overlap" VS "Small Overlap" testing, a couple inches to the right or left can significantly determine how differently exact same cars will perform, in terms of where the impact is.

The good thing is the IIHS forces automakers to pretty much cover all their bases in terms of having to perform right in safety, which benefits us all. What I'd like to know is what M-B says about why the Side Airbags didn't deploy. Is it by design, or was is a fluke? If it's by design, then it's idiotic because unless they have a case that more airbags deploying when not vitally necessary can do more harm than good, then we can use all the protection that we can get, case in point: This test. If it's a fluke, then hopefully they'll retest a bunch of cars and see if it's a reoccurring problem, and if so, issue a recall. If it's by design, then it would be nice if they did recall all cars to re-engineer the trigger points of the side airbags, but that's highly doubtful.

One thing that struck me as incredibly odd is the Audi A4's test data. The C has faults in that the wheel intrudes into the cabin and the side airbags didn't deploy, but the structure of the upper cage held up seemingly the best of the group (and the interior didn't fall apart/split in half like the 3-Series'). I always thought Audi built some of the strongest body shells and safest cars, and again, I wouldn't write them off due to one out of a thousand types of crashes.... but the A4's cage collapses completely, I never expected that from Audi.

bhamg

Just got around to watching this video and I agree. From above, the door seems to buckle rather easily and eventually pops open...at the point the door has completely yielded its resistance the A-pillar folds back and the driver is toast. Didn't the pedal trap the dummy's leg which had to be cut free in the C? My guess is in that happenstance it'll be a long time before one is walking normally.

WEBSRFR

No, I am not "confused" by this test. It's these kinds of arrogant and ignorant statements from Mercedes that really makes me upset. I know overall they build very safe cars but if they screw up with a vehicle design on safety (and this would not be the first time), admit it, shut up, and fix it. I am sick of these BS statements that seem to assume we are dumb.

The fact of the matter is yes, if it was a deformable barrier, then the impact would be less...

-- BUT --

Is that really the yardstick we should use? Is this test so hard that Mercedes needs to count on a soft target for their design to perform well when Acura and Volvo performed much better with a harder target? Give me a break.

You don't decide what you will hit in an accident. It can be a soft car, or it can be a concrete pylon on a bridge. If the life of your family is at stake, would you rather have the vehicle built to handle crashing into a a little egg-basket of a car or a block of concrete?

It is a Mercedes we are talking about and the safety of the occupants for crying out loud. Build the damn thing to handle the block of concrete and it will nicely handle any soft targets for free. What about this is so hard for Mercedes to understand?

I don't want to my car designed to handle a crash with an egg basket on wheels. Raise the bar so it can handle a severe impact with something more solid, as Volvo and Acura has done.

IMHO Mercedes' statement is akin to telling us:

"Well we know what is best for you so we designed the car to handle a crash with a small car that can deform in a crash. If you have an accident, please don't hit anything harder than a small car. At Mercedes we feel you should not crash into anything more solid than a smaller car"

"Oh and also our engineers have decided in a severe offset crash like this we should save the side airbags so that the people in the junk yard can make some money selling the airbag. Therefore we decided to not deploy it in a severe offset frontal crash. So if you are involved in a severe offset frontal crash, in addition to not hitting anything too hard, please do your best to keep your head straight so as to not hit the side components or the A pillar of your car. Oh and also close your eyes before the crash so that if the side window should shatter, the glass will not embed in your eyes."

220S

I agree. Mercedes could have tried to explain the kinematics of their own literature instead of assuming their customers are too stupid to even try to understand it.

There are hundreds of studies out there covering small offset frontal collisions. Just do a search on Google Scholar.

Mercedes didn't do the small offsets like Volvo did. They point to a study by Stephen, Wilhelm, and Hermann (Steyr-Daimler-Puch Fahhrzeugtechnik.) The theory is that the car should be designed to slide away from a small offset. The front wheels will normally be turned to the right of the driver (in a two car offset frontal this will usually be the case) and the wheel will act as a barrier. They elected not to use a rigid barrier because they say it is a fact that crash tests against rigid and/or 100 percent barriers do not reflect real life accident situations. That is why supplementary “Offset Deformable Barrier” (ODB) crash tests were introduced in the 1990s.

Volvo found this also to be true after the 1990s. But they had already initially tested for a rigid structure small offset which led them to design a much more stronger cabin. After they built their test facility in 2000 (with two tunnels which can turn at any angle on air suspension devices) they tested using ODB tests which in their case was using two cars aimed at each other to hit in a small offset.

Mercedes Benz engineers designed vehicles to perform well against their own 40% offset frontal crash test. They did not do small offsets like Volvo had been doing since the 1980s.

The Winkler Stephen paper (above) asserts that: "the main task is to make aware the fact, that frontal crash compatibility for small lateral overlaps with “full” hang accident mechanics is not realistic. Regarding to the described benefits of the glance-off effects, a new crash test procedure should be introduced which promotes the conversion into a sliding collision."

This is what Mercedes is implying. That could be an argument against the IIHS model of small offset frontal testing. But Mercedes should be explaining it to their customers instead of telling them that they, as customers, are not worth the effort.

On the other hand, Volvo knows this too but they already had developed a stronger cage and the glance off effects of wheel positioning based on their own early rigid barrier tests (and their later ODB tests.)

And there is still the issue of the side curtains not deploying and too much shoulder belt webbing spooling out of the retractor in the Mercedes C Class. Those could be addressed right away without any major re-designs.

Volvo ran a full page ad today with the headlines: "This is bound to have a huge impact on Mercedes, BMW, and Audi."

It has been conceded that hitting a rigid barrier at a small offset on the driver's side is rare in the real world by all manufacturers and the majority of studies. Someone coming over the center yellow would more likely mean that you're going to turn away and there would be a glance off situation (plus your wheel would be turned to the right.) But what if you end up hitting a rigid pole on the side of the road and you have a passenger in the car with you. I wouldn't want to be that passenger if I was in a Mercedes, Audi, or BMW.

Whether the small offset into a rigid barrier doesn't reflect the real world doesn't really matter in the end. Volvo (and Acura) have clearly designed their vehicles to withstand such a scenario. There's no reason why Mercedes couldn't have done the same. And you better believe that they sure will now. Because those "confused consumers" speak with their wallets.

WEBSRFR

@220s, is this the advertisement you are talking about?

http://www.sandiegovolvo.com/public/...top-rating.pdf

Excerpt:


No two drivers, or accidents for that matter, are the
same. That’s why every year the Insurance Institute for
Highway Safety (IIHS) specifies a battery of crash tests,
from many different angles, to help consumers make the
right choices when it comes to automobile safety.

But tests, much like accidents, can sometimes come out
of nowhere. Case in point - the new Small Overlap Frontal
Crash Test prescribed by the IIHS. A crash test where 25%
of a car’s front end on the driver’s side strikes a 5-foot-high
barrier at 40 miles per hour. A test that has never been
conducted before in the U.S. or Europe.

The result? Predictable, to say the least. Only one
European luxury sedan earned a “good” rating from the
IIHS—the 2012 Volvo S60. Now let’s put that in perspective.
In the very same test, both the Mercedes-
Benz C-Class and the Audi A4 earned a
“poor” rating, while the BMW 3-Series
earned a “marginal” rating. In addition,
the Volvo S60 also scored the highest
in Structural Integrity among all cars tested. That’s crucial
because in certain crashes, a robust structure along with a
strong safety cage work in tandem to absorb much of the
impact thereby helping protect the occupants.

While we’re flattered to receive such high praise
from the IIHS, we can’t say we’re terribly surprised. We’ve
been performing hundreds of similar Small Overlap Tests
(thousands if you take into account the other crash tests
we’ve conducted) since the 1980s. We’ve also been
diligently taking down notes and keeping the results in mind
when designing newer models like the 2012 S60. So while
most automotive manufacturers are content to design their
cars to excel in existing tests, we are continually looking for
new opportunities to improve on passenger safety. Because
at Volvo, we don’t build cars to merely pass crash tests; we
build them for the people who will eventually drive them.
And that evidently is making a big impact.

220S

Yeah, that's it. It was a full page ad in this Sunday's New York Times.

Like it says in the copy, they've been doing small overlap testing since the 80's (and before anybody else.) And since the 1940's, cabin structural rigidity has always been their focus in respect to safety. Which is actually what the IIHS has been saying all along to the manufacturers: build a stronger safety cage.

220S

p.s., just wanted to add this: in another thread (and here too) it's mentioned that the Acura and Volvo don't "track as straight" as the Mercedes into the barrier and that they glanced off. Well, that's the whole point and is at the heart of the Stephen, Wilhelm, and Hermann study. The idea is to have a glance-off in a small offset frontal. And to have the wheel either come off (like Volvo designs it) or to turn sideways (what the study calls a "positive wheel rotation.") The C Class clearly failed in both aspects (as did the Audi.) The best design is to be able to "slide away" (as the study calls it) and to have a positive wheel rotation. It's the same idea behind the new pedestrian safe flat nose designs. It's not just structural underneath, but also needs to be part of the sheet metal.

It's a good thing that a car slides off in a crash test like this or the wheel comes off or shifts laterally. That's ideal. And again, was the whole point behind the Steyr-Daimler-Puch Fahhrzeugtechnik paper. That is what they are advocating.

otakki

I have nothing against Volvo. But it's obvious that Volvo is jumping on the opportunity to run ads against MB, BMW, and Audi on this small overlap crash result. I saw one online yesterday that goes something like, "Sorry to Mercedes, BMW, and Audi for crushing your parties."

Overall, this iihs small overlap testing sure has raised on a lot of interesting info I have not come across before. I'm sure all these discussions will lead all the manufacturers to enhance the safety of their cars. That, in the end, will benefit all drivers. Of course, it is MB's attitude that makes many unhappy.

I am sure many have gotten a survey from AMG today. I have made it clear on that survey that safety is my priority and ensuring their cars to be safe for this short overlap and other crash testings will be paramount to me in my becoming their customer again in the future.

K-A

The uproar here benefits us all as the more M-B perfects their safety standards, the better for us all. But some perspective VS Volvo is that in the IIHS' most recent fatality data, in the category where they had M-B and Volvo in the same segment going head to head, the ML had half the fatalities than the XC90 did.

The new S60 is statistically about faultless in standardized tests, which is very impressive, however in all the other IIHS data at hand, the C-Class performs as good as, or better than it. For example, both look about untouched in the IIHS side crash test, with the C showing slightly less intrusion into the cabin, namely less compromise of the lower portion of the B Pillar. Also, the C has a slightly stronger roof. Before I'd credit Volvo as a superior to M-B when it comes to safety knowledge and real life performance, I'd need to see more real life fatality/injury data, of which for whatever reason the IIHS doesn't print for most of their models.

Also, remember that the S60 is a 2011 debut while the W204 is a 2008 debut. The W212 would be a better comparison to see how M-B were engineering their cars closer to the launch date of the S60. As an example, the W212 had more advanced steels used throughout the structure that M-B engineers claimed weren't available during the time of the W204's development while as well using more High Strength/Ultra High Strength/Mega High Strength steels throughout the structure in it than they did in the W204 (I think both set a record in the car industry during their respective launch years, I know the E did).

bhamg

Lots of good info here...thanks. Now let's see what M-B does about the airbag situation that this latest test has brought to light.

WEBSRFR

Be careful when you consider the Volvo XC90 as you really have to keep in mind that car was developed in 2000 and came out in 2003 and due to Volvo's financial problems they have not updated it in over 10 years. It is essentially 15 years old technology while Acura/Mercedes/BMW have advanced about 2-3 generations with safety advances made each time. It is a testament to Volvo's commitment to safety that their 15 year old design is even still very competitive with the latest and most advanced SUV designs of other manufacturers.

The fact remains that if you consider a modern Volvo like the S60 with all of Volvo's financial problems, they put their limited resources on safety first when they designed the S60. They did not design the S60 to pass the tests, they went beyond that and it shows. 220s provided a lot of useful info in this regard.

I also have to add that I would not be so upset over this whole situation if Mercedes demonstrated better attitude. Unlike Audi who accepted the poor design and pledged to fix it, Mercedes pretended like nothing is wrong when there are photos of the driver crashing into the deformed A-pillar with no side air bags being deployed. Do they think we are blind or dumb?

All they had to say is that they are going to study the accident and make the necessary improvements to protect their customers and demonstrate that when the next crash test comes out. Their BS statements aside, they will be forced to go back to the drawing board and fix things because starting in two years, IIHS will not designate a car that failed this test a 5-star rated best pick.

amcguru

Hi folks. I have been a M-B dealer tech since 2000 and as such know these cars very well inside & out. Regardless of how the car performed or what the official response from M-B was, don't think for second you are driving an unsafe car...it's just as safe as it was before the IIHS released the test results. On several occasions, customers shared their own stories with us of how well a Benz protected them and their loved ones when the other parties didn't fare as well.

There were several posts earlier suggesting that M-B add a crossmember between the A-pillars & an upper structural member behind the fender like Volvo has. Guess what folks...the W204 has both. In fact, the upper fender structural member was first introduced in late '97 on the w163...every new chassis since has been built with this structural member. I can also confirm that every M-B since the W201 has a beefy crossmember behind the dash that's secured with several bolts to the A-pillars & trans tunnel. Honestly, I think had the wheel seperated from the vehicle, intrusion would have been minimal.

For many many years, M-B has dispatched it's own investiagtion teams to the sites of accidents in Germany to study the scene, vehicle deformation behavior, injuries to occupants & enviromental factors that may have contributed to the accident. One of the first things they learned was, the more you optimize vehicle structure to excel in one particular impact scenerio, the less effective it may be in another. Example, a very stiff front structure will provide good protection in a small overlap crash but can result in very high G-forces & internal injuries for the occupants in a more full frontal crash. This is balancing act they have spent years refining to build a car that provides the best all around protection possible be it front, angle, side, rear or rollover impacts.

Many of you are concerned as to why that the side & curtain bags did not deploy. I suspect they worked as designed as M-B takes a very conservitive approach to airbag deployment stratagies. M-B's accident investigation team learned that in multi car accidents, occupant injuries offen occured durring the second or third impact event. Example, a oncoming car crosses the center line on a rain slick road and hits you in an offset frontal impact...your car is sitting stopped in the middle of the road at a 45* angle. Your front airbags & seatbelt tensioners deployed...your shaken up but OK. Then, a second later, you are T-boned in the drivers side by a vehicle that was following you too closely & could not stop or never even made the attempt as their eyes were not on the road ahead of them. The side bags then deploy providing you protection you would not have had if they had deployed in the frontal crash...one more example of providing the best all around protection possible.

Something else to keep in mind is the w204 design dates four years prior to the S60...this means teh Volvo benifits from four years of structural safety advancments that have taken place in that time. Example, IIHS mentioned the large steel strut joining the upper & lower structural members together as being part of the reason for good performance. The new for 2012 w166 incorporates the same design & I think it's safe to assume all new M-B chassis from here on will as well. Mercedes has a long history of building a very safe vehicles & that won't change.

Below are links to a video & comercial that showcase M-B safety fron the 1980's that many other automakers still have not matched.

Forward to 2:04 if you prefer not to watch the entire video.

otakki

Thanks for the reassuring and thorough explanations. Those comments do make me feel better.

Wow, good post with that 60 minutes videos. I saw that a long time ago but never thought I would see it again.

DuaneC63

Yah first thing I think of when buying a car is the "overlap front crash test" . If you buy a car based on crash tests, everyone would drive a Volvo. What an exciting world that would be. If I'm in a crash it's not going to be at 35mph....its going to be at 135mph and nothing is going to save my *** then.

K-A

Excellent post and spot on. This answers literally everything.

Naysayers shouldn't doubt M-B's crash investigation and approach, as M-B has always proved they know safety better than anyone, including IIHS. It makes sense that the Volvo's 4 years of time allowed for structural-material advancements allowed it to focus more purely on this scenario, and if the W204's wheel would have broken off, it would probably see as little to if not less damage than the Volvo. Also, the "balancing act" is very important to note, and is why M-B doesn't always do "perfect" in every which standardized test, and why they always say "real world safety". Anyone can pass a test, but not everyone can design a car to TRULY perform in the multitudes of real life situations, and walk that find "balancing act" line so well.

Also, the 2012 ML is a FLAWLESS portrayal of standardized safety supremacy. The roof strength alone is almost 30K lbs of withstanding force (as tested by IIHS). That is a RECORD for ANY car tested in existence. So it shows that M-B are finding ways to pass tests with flying colors, probably still maintaining that "real world supremacy" aspect.

amcguru

[QUOTE=K-A;5369255]Excellent post and spot on. This answers literally everything.
QUOTE]

Thanks...there's a few of us dealer tech's with our head on straight.

If memory serves correctly, all of our cars perform very well in the roof crush tests. Not sure how many other manufactures can say that. Something else I negleacted to mention...M-B began optimizing structures to manage offset impacts in the '70's while designing the w126. As a result, very few Benz earn a five star rating in the U.S. govt. full frontal concrete wall test...most earn four stars because the front structure is too stiff for this unrealistic test.