Vs Maybach vs Mercedes - UHSS vs regular steel

[K-A]

Good points. And yeah, the thing should be at least in the high 3K lb range.

M-B were never really known to pass tests with flying colors, but they always lead when it came to saving lives in the real world (both W210 and W211 had the lowest fatality rates for any car aside from larger ones when the IIHS released those facts in 2007). I still felt uncomfortable when I had my W211, knowing how "weak" the B-Pillar was, in the event of a crash identical to the IIHS one, but had the confidence that I was still in an M-B, and the W211 was still known to be one of the safest (life saving) vehicles on the road (statistically).

The W212 obviously fixes the "Test" portion of its performance, of course. I think that M-B definitely went several extra miles here, because even if the IIHS went with a larger/faster device, the W212 would probably hold great stability, considering in this Test, it looks unscathed. I'd bet that in a harsher Test, we'd see more intrusion, however, probably on par with what we see from cars right now currently, that are still passing the Test well, but see intrusion into the cabin (even the F10, etc.).

 

[ObsessedWithCarSafety]

M-B were never really known to pass tests with flying colors, but they always lead when it came to saving lives in the real world (both W210 and W211 had the lowest fatality rates for any car aside from larger ones when the IIHS released those facts in 2007).

The one thing that sucks about those per-model fatality stats (IIHS) is: since they're deaths per million registered vehicle years rather than deaths per accident (or, better yet, deaths per potentially fatal accidents), don't demographics and other factors besides actual vehicle safety play a large role in the rate, making it not-so-very-real-world? For example, Mercedes E class drivers may be on average older, more cautious drivers than drivers of other models, making the death rate per million registered vehicle years relatively low, but not necessarily meaning that in the event of a bad accident the driver of the E class would be better off than someone in a car that has a higher death rate.

M-B were never really known to pass tests with flying colors ... The W212 obviously fixes the "Test" portion of its performance, of course.

Good point... that's another thing. For example, look at the IIHS test results for most Volvos (and Mercedes too). Not terrible, but not as good as you might think ("Volvo = safety", etc etc). So what's really going on here? Does this mean that overall, Volvos and Mercedes are less safe than cars that perform better according to the raw data in the IIHS's tests, and the whole "safety" thing is mostly marketing BS? Or is it that Volvo and Mercedes design their cars to be as safe as possible in a variety of real-world accidents, rather than designing them to pass a test?

Even if the latter case is true, it's still kind of disconcerting that a car made by companies that spend so much R&D on safety, don't perform as well in the tests as cars made by companies that don't market their cars as being very safe. Especially, but not limited to of course, the side impact tests: in my opinion, the IIHS test is fairly real world (save for the wide surface area and relatively low weight of the barrier), as it's basically a simulation of someone blowing a stop sign at an intersection... and yet performance in those tests of certain MBs, Volvos, and so on leave a lot to be desired.

It'd be cool if Mercedes, Volvo, etc., were a bit more open about this sort of thing.

 

[K-A]

All good points.

To further touch on the "strength" thing. M-B stated that they pulled no punches on the W212, supplying it with the most strong materials of any car in history, and the strongest materials available at the time of its build (some steels that weren't even available a couple years prior) (Mega High Strength Steels, etc.).

I might have already posted all these, but to post some side by sides, one with the old E, and one with the brand new, very strong 5 Series, you see that the W212 is obviously a statement of structural integrity of sorts. At the bottom, is an Award showcasing the W212 as having the best body structure of any car in 2009, including much more expensive cars.

 

[coolraoul]

Always this discussion again...

KA, you say that the W211 wasn't the strongest car, esp. on the B-pillar. Yet it is very safe.
Doesn't that mean thay safety is a little bit more complicated than just putting some UHS here and there? That even the overall rigidity of the car's structure is only telling half the story in terms of safety?

A car that is too rigid can be bad for the occupants by creating too much of deceleration for the human body to withstand.

The geometry of the chassis, the design of the crash structures, firewall, safety cell, the way the different pieces composing the structure will interact and deform, are more important than the sheer type of metal used. You can have weaker materials performing better than stronger ones, because arranged in a way so that they work better with the surrounding structures.

And you can have a part made of UHS that is not stronger than the one made of conventional steel... because the UHS is used for weight saving, thus the piece will be less massive than the conventional one. It will be lighter, not necessarily stronger.

Hearing you, making a safe car is the easiest thing in the world: just put 1000tons of IHS and voilà. Stupid carmakers that perform hundreds of tests while they just should use different steels... They should just use railways instead of bumpers and that's it.


You are oversimplifying the safety engineering, KA, imo, reducing it only to a UHS percentage. It's much, much more complicated than that. Why should supercomputers need days to generate the data of a crashtest if it was so simple? Just enter the IHS ratio, press enter and there you have your result... Why even bothering to make crash-tests any more?


@ Obsessed: many carmakers engineer their cars specifically to pass said test with flying colors. Meaning they'll get a superb result at that test, not necessarily however in real life.
While Mercedes and Volvo, for instance, spend lots of time and money studying real-life crashes, trying to get all types of accidents covered by their crash structures.
Of course, if you protect from many types of accidents, you may not get as much points in a specific crash as a car engineered just for it.

This is why Mercedes and Volvo are not always the best in the crashtest scorings, but still the safest IRL.

 

[bum-man]

Wow I had no idea the W212 was that strong! It looks like you could just take it to a body shop and have them pull out the dents. Well done Merc!

Now I wonder how the new A6 will stack up?

 

[bum-man]

Had to post this. I'm terribly impressed with their consistency now. Look how well the B-pillarless E-coupe performs compared to other makes!

Model------------------Curb weight (lb)------------Peak force (lb)----------Strength-to-weight ratio
Mercedes E class 2-door
2010-11 models-----------------3,736---------------------20,852----------------------5.58

Mercedes E class 4-door
2010-11 models-----------------3,880---------------------20,961---------------------5.40

Volvo S80
2007-11 models-----------------3,756---------------------15,989---------------------4.26

BMW 5 series
2011 models---------------------3,803---------------------15,364---------------------4.04

Mercedes GLK
2010-11 models-----------------4,157---------------------26,647---------------------6.41

Volvo XC60
2010-11 models-----------------4,172---------------------21,828---------------------5.23

Audi Q5
2009-11 models-----------------4,237---------------------18,684---------------------4.41

Mercedes C class
2008-11 models-----------------3,510---------------------18,826---------------------5.36

Audi A4
2009-11 models-----------------3,523---------------------16,197---------------------4.60

Source: IIHS

 

[Giannis]

Always this discussion again...

KA, you say that the W211 wasn't the strongest car, esp. on the B-pillar. Yet it is very safe.
Doesn't that mean thay safety is a little bit more complicated than just putting some UHS here and there? That even the overall rigidity of the car's structure is only telling half the story in terms of safety?

A car that is too rigid can be bad for the occupants by creating too much of deceleration for the human body to withstand.

The geometry of the chassis, the design of the crash structures, firewall, safety cell, the way the different pieces composing the structure will interact and deform, are more important than the sheer type of metal used. You can have weaker materials performing better than stronger ones, because arranged in a way so that they work better with the surrounding structures.

And you can have a part made of UHS that is not stronger than the one made of conventional steel... because the UHS is used for weight saving, thus the piece will be less massive than the conventional one. It will be lighter, not necessarily stronger.

Hearing you, making a safe car is the easiest thing in the world: just put 1000tons of IHS and voilà. Stupid carmakers that perform hundreds of tests while they just should use different steels... They should just use railways instead of bumpers and that's it.


You are oversimplifying the safety engineering, KA, imo, reducing it only to a UHS percentage. It's much, much more complicated than that. Why should supercomputers need days to generate the data of a crashtest if it was so simple? Just enter the IHS ratio, press enter and there you have your result... Why even bothering to make crash-tests any more?


@ Obsessed: many carmakers engineer their cars specifically to pass said test with flying colors. Meaning they'll get a superb result at that test, not necessarily however in real life.
While Mercedes and Volvo, for instance, spend lots of time and money studying real-life crashes, trying to get all types of accidents covered by their crash structures.
Of course, if you protect from many types of accidents, you may not get as much points in a specific crash as a car engineered just for it.

This is why Mercedes and Volvo are not always the best in the crashtest scorings, but still the safest IRL.

Very good post there Amaury!

So, some points that were raised from Amaury:

First of all, Safety is not a first-degree equation in one variable % of UHS. The most important part in determining the safety of a certain vehicle, is the design of the structure and its ability to absorb the energy from the impact. The various types of steel are just a tool to make that happen.

An example. Imagine that you are in a box that is made of 100% UHS steel and has no ability to deform. You are sitting on a seat that is firmly attached to this box, you wear your seatbelt, and you are driving at 31mph, like the NHTSA crash tests. And then you crash into a wall. Would this box save your life?

The answer is no, because the box will absorbe absolutely no energy, as it will not deform. Engineering fundamentals. The energy equals the area between the curve and the deflexion axis:

The above diagram is used as an example and shows the behaviour of structural steel under loading.

Another point brought up by Amaury, is that the percentage of UHS steel only tells half the story, as it can be used for lowering the weight, instead of increasing the structural rigidity of the chassis. You could have a car with 15% UHS steel, but that would just substitute a certain amount of normal strength steel, of the same overall strength, but with much more weight.

 

[K-A]

Always this discussion again...

KA, you say that the W211 wasn't the strongest car, esp. on the B-pillar. Yet it is very safe.
Doesn't that mean thay safety is a little bit more complicated than just putting some UHS here and there? That even the overall rigidity of the car's structure is only telling half the story in terms of safety?

A car that is too rigid can be bad for the occupants by creating too much of deceleration for the human body to withstand.

The geometry of the chassis, the design of the crash structures, firewall, safety cell, the way the different pieces composing the structure will interact and deform, are more important than the sheer type of metal used. You can have weaker materials performing better than stronger ones, because arranged in a way so that they work better with the surrounding structures.

And you can have a part made of UHS that is not stronger than the one made of conventional steel... because the UHS is used for weight saving, thus the piece will be less massive than the conventional one. It will be lighter, not necessarily stronger.

Hearing you, making a safe car is the easiest thing in the world: just put 1000tons of IHS and voilà. Stupid carmakers that perform hundreds of tests while they just should use different steels... They should just use railways instead of bumpers and that's it.


You are oversimplifying the safety engineering, KA, imo, reducing it only to a UHS percentage. It's much, much more complicated than that. Why should supercomputers need days to generate the data of a crashtest if it was so simple? Just enter the IHS ratio, press enter and there you have your result... Why even bothering to make crash-tests any more?


@ Obsessed: many carmakers engineer their cars specifically to pass said test with flying colors. Meaning they'll get a superb result at that test, not necessarily however in real life.
While Mercedes and Volvo, for instance, spend lots of time and money studying real-life crashes, trying to get all types of accidents covered by their crash structures.
Of course, if you protect from many types of accidents, you may not get as much points in a specific crash as a car engineered just for it.

This is why Mercedes and Volvo are not always the best in the crashtest scorings, but still the safest IRL.

Of course I realize this, but I thought we were simply debating certain elements of safety, especially in this Thread, one being Steel strength.

Also, we don't have much to debate when it comes to the other stuff, so all we can really do is read what they tell us, and analyze what we have at our finger tips. One reason why brand name means a lot to me in Safety, is in that "benefit of the doubt"/trust aspect, i.e, if they've earned it.

M-B I trust is a brand that will continuously refine their cars' safety. So, the strength of steels, and better standardized test scores, are just a way to tell us that (I trust, and hope).

For example, when I analyze a cars safety, I put a lot of focus on the hood length, as that is your pillow basically, in terms of how much force it can absorb. There's tons of elements to safety, and I am more than aware of that. Structural integrity, and BUILD QUALITY (materials used, how they're pieced together, etc.) is a huge part of that. I mean, these engineers aren't buffoons, it's not like they're going to make a car as indestructible as the W212 is when coming out of an IIHS Side Test, and forget to put focus on G forced/load, and crumple zones.

And, in the allowed mass of a car, it will take A LOT of standard "weak" steel to get the same strength as slimmer U/M/HSS. It's not like these people can make A-Pillars the width of chimneys. And don't forget, that in most brands, as they use higher strength steels, they also increase mass (M-B for example, has done this with the new E VS the old E, the new one uses stronger materials, and thicker panels/higher beltline as well).

 

[K-A]

Wow I had no idea the W212 was that strong! It looks like you could just take it to a body shop and have them pull out the dents. Well done Merc!

Now I wonder how the new A6 will stack up?

Yup, it's very worthy of being called a "Tank", just like the old M-B's were.... Although, this out-Tanks them by a long-shot. A proper and valid evolution.

The Audi should do great. Audi has been using the some of the strongest materials around, and building structures that withstand forces exceptionally for quite some time.

 

[coolraoul]

For example, when I analyze a cars safety, I put a lot of focus on the hood length, as that is your pillow basically, in terms of how much force it can absorb.

The hood length is not worthy of attention (unless you're talking about a midget car).
It's not like the whole front is the absorption zone: there are some details, like a motor for instance, under this hood.
Having a long hood, with a long motor underneath, doesn't necessarily provide you with more crumple zone that a shorter hood with a small motor underneath.

You need to consider how the motor will deform itself, how it is implanted and how it will move during the shock.
You don't want your V8 sitting on your knees after the shock, do you?

Good example of that is the A-Class Mercedes. Short hood, but the motor is specially conceived and specially implanted so that, instead of moving forward to the passenger's cell, it will "glide" along the firewall and end up under the car. Providing enough space for the front of the car to absorb the shock.
Here, clever engineering allowed a very high level of safety with a very short hood.

Comparatively, some BMWs were not so safe because, despite their long hood, their inline-6 engines were too long and positionned too far back (weight distribution), not letting enough space for deformation... and coming into the passenger's cell.
One of the reason Mercedes gave when they switched to V6 designs.

So here again, you are taking into account elements that are not necessarily the good ones.

Again, not saying a car is safer with a smaller motor: motors are themselves part of the deformation process, and engineered to deform exactly like they should to provide crumple space. They are part of the safety design of modern cars.

Car safety is a billion$ R&D business.

Trivial elements like 4cms more hood length (not even taking into account how far back the motor goes, for better weight distribution, direction passenger's cell) are totally inconsequential.
And the safety cell is not resumed to A-pillars, the firewall is a vital element of it because it is it what protects you from intrusion from what sits before you.

 

[Wolfgang]

It's also a matter of where the driver sits as many miles are driven with just the driver in the car. If she would be sitting in a central location, a side impact could penetrate quite a bit, absorbing impact energy, and probably with a lower chance of causing injuries. Mercedes first mentioned a central seating location as far as I know in 1948, in the Terracruiser patent authored by Bela Barenyi. Lateron it appeared again in the F100 concept in 1991.

Béla Barényi and the discovery of passive safety | Daimler Global Media Site > Heritage > Technology > Safety

 

[coolraoul]

True, you can notice in some cars the seats are implanted quite far from the doors, maybe to compensate a weaker side structure.

There are so many elements to consider to even start to comprehend what car safety means...

 

[ObsessedWithCarSafety]

The hood length is not worthy of attention (unless you're talking about a midget car).
It's not like the whole front is the absorption zone: there are some details, like a motor for instance, under this hood.

So here again, you are taking into account elements that are not necessarily the good ones.

Trivial elements like 4cms more hood length (not even taking into account how far back the motor goes, for better weight distribution, direction passenger's cell) are totally inconsequential.
And the safety cell is not resumed to A-pillars, the firewall is a vital element of it because it is it what protects you from intrusion from what sits before you.

I'm no expert, but I have to disagree with you here.

First of all, longer hood doesn't automatically equal longer motor.

Second, let's say that Mercedes designed a car -- with safety in mind, as with the E-class and their other cars -- with a hood that was 10 feet long (play along...).

You're telling me that the Mercedes with the 10 foot long front-end will provide no better protection to the occupants than the A-class would with its super short front-end? G-forces would be the same, the amount of intrusion into the cabin would be the same, etc?

True, a longer front-end doesn't automatically mean a safer car, but I'd be willing to bet that if the E-class's front end was, say, a foot longer, and the engineers designed the car properly, that its frontal crash performance would be superior to what it is today.

 

[coolraoul]

What I say, is that you cannot say:

"Car A has a longer hood, thus must be safer."

Because it's not necessarily true, and depends from how the crumple zone is conceived, etc etc.

 

[Giannis]

"Car A has a longer hood, thus must be safer."

The length of the hood has nothing to do with safety. The hood is only supposed to protect the engine and be soft in case of an accident involving a pedestrian.

The hood is supposed to work as a slab, thus it cannot bear any axial loading. So, it doesn't flex/deform in its level/area, but it bends.

What is important are the two "cantilevered beams" that support the engine and the front end. It's those two beams that deform and absorb the most of the impact energy. These two beams are part of the chassis, while the hood is not.

The two beams that I refer to, can be seen in those two photos in red and light blue colour:

 

[bum-man]

Giannis, they mean long front end. Long hood = long front end.

 

[Giannis]

Giannis, they mean long front end. Long hood = long front end.

Oh!

 

[K-A]

What I say, is that you cannot say:

"Car A has a longer hood, thus must be safer."

Because it's not necessarily true, and depends from how the crumple zone is conceived, etc etc.

Of course. But once again, taking factors that we have at our fingertips, and comparing cars from the same manufacturer (Mercedes, for example), I'll take the longer hood every time, for protection.

I.e, a Merc with a longer front-end/hood, will most probably be better at absorbing energy than a Merc without a shorter one.

This kind of shows what I mean. This is comparing a newer, stronger bodied, more advanced (assuming, because it's of a newer/evolutionary state of engineering from Benz) W204, with a W211. Both do their jobs great, and both are crashed into identical barriers at identical speeds, but as you can see, the damage is further away from the 211's cabin, which is a benefit of its long front end. Now, the 211 is also heavier and larger, so a 204 hitting a 211, even with the 204 being a lot stronger, would be an interesting "comparison" to see how each fares in a standardized test. This brings a huge other factor of safety into play: Weight and mass

.

 

[ObsessedWithCarSafety]

To further touch on the "strength" thing. M-B stated that they pulled no punches on the W212, supplying it with the most strong materials of any car in history, and the strongest materials available at the time of its build (some steels that weren't even available a couple years prior) (Mega High Strength Steels, etc.).

...

Cool stuff. You wouldn't happen to have a link to that statement would you? Searching Google for MHSS, the only thing it leads me to is here.

 

[ObsessedWithCarSafety]

It's also a matter of where the driver sits as many miles are driven with just the driver in the car. If she would be sitting in a central location, a side impact could penetrate quite a bit, absorbing impact energy, and probably with a lower chance of causing injuries. Mercedes first mentioned a central seating location as far as I know in 1948, in the Terracruiser patent authored by Bela Barenyi. Lateron it appeared again in the F100 concept in 1991.

Béla Barényi and the discovery of passive safety | Daimler Global Media Site > Heritage > Technology > Safety

Cool. I've thought about center-positioned seats / seats positioned further from the doors myself.

For those that don't need to haul more than 3 people, one center front seat and two center rear seats would definitely provide superior protection to passengers in side impact crashes compared to the traditional seating arrangement.

M-B should make an E-class with seats in the center, for us safety freaks.