Front & Side Crush Zones

**niky** · May 21st, 2008 12:02 PM

Originally Posted by flat_four_fan

Kaya nga yung mga pick-ups in ANCAP crash tests are given a good in side impacts without even crash testing because of the towering ride height.

And so? That means those ANCAP boys are nincompoops. You can't just assume a car will do well. And note, many pickups score much poorer than compact cars in all other crash tests. A Jazz or Vios is a four-star EuroNCAP car, while certain local pickups are in the 1-3 star range.

Originally Posted by niker

I guess that if all sedans like city, civics, altis, etc. are faced out and all of us used SUV. Yearly accidental death can be lessened by more than half. If there is one million victims yearly. 500,000 can be saved if those sedans are removed from the street.

This is false. You see more crashes for smaller vehicles and more fatalities simply because younger people can afford them, which means that more reckless drivers buy small cars than large cars (though many reckless drivers buy large cars).

If the Philippines were a richer country, you'd have more SUV accidents... oh... wait... we have TONS of jeepney accidents and AUV accidents already. Where people actually get killed.

----

Like I've said, your modern compact can withstand impacts as well as or better than many larger vehicles.

What we're counting here is structural stiffness and the ability to transmit forces from one end of the vehicle to the other. A smaller car will carry less kinetic energy and less potential energy than a larger car.

What this means is that if you're driving the smaller car into an obstacle, you're carrying less force and will cause less damage to yourself and other people. If someone drives into you, your small car can absorb the impact force and then be shoved aside.

I've seen lots of people in large vehicles killed in collisions with trucks, even with similar bumper heights.

Even if a truck may override your front bumper in a small car, there are many people who've walked away from truck collisions with their compacts. Trucks are mandated to have bumpers low enough to engage the crash structure of cars nowadays (that's front, though.. if you run into the rear of a truck, you're simply stupid) and even when a car goes under a truck, the cabins of most compacts are ultra-stiff and provide great crash protection. many trucks have older or less efficient cabin designs that can crumple under pressure (note the Everest cases, the Ranger and DMax EuroNCAP scores, etcetera...). I've seen people walk away from crashes in small, light cars like the Impreza, from underneath trucks, with nary a scratch.

A well-designed truck can score well... the Strada scores 4 stars on EuroNCAP. And i trust the EuroNCAP because they publish results showing deflection and structural damage, unlike others who merely state how many "stars" a vehicle gets.

But other vehicles have fared poorly. The Navarra received zero stars. One with a strikethrough. Theonly other vehicle to score so lowly is the Chevrolet Spark.

What you're looking at here is how much attention manufacturers pay to crash integrity. Because compact cars must be sold in the European and US markets, where crash survivability versus large cars is important, they're over-engineered.

Most pick-ups and SUVs are based on old platforms. And they have lots of weight. No, not just the weight in front... everywhere! To keep from buckling, the crash structure of a pick-up must survive the impact and the forces of momentum applied to it from the weight of the vehicle trying to push it through the obstacle. As a consequence, they have to be designed much stronger to survive an impact... but they're not. Most people assume that the extra weight will save you, but that's just not universally applicable.

Look up the EuroNCAP website. The Honda Jazz scores higher than the old CR-V, but lower than the new one (simply, the new CR-V is a newer product). The new Civic scores much higher than the old CR-V, and is just one point behind the new CR-V in side impact tests. Both get four stars overall.

So... if your only compunction in upgrading to a new Civic or City is crash safety compared to your old CR-V, there's your answer. The Jazz is just as safe as the old CR-V, the Civic is much safer. And they're safer on the road because they're more maneuverable and have less of a chance of rolling over or going out of control than an old CR-V. The major reason you see these cars in crashes is because they're affordable, which means younger, dumber people drive them, people who've never driven a car before... period. That's why you see a lot of Fortuner and Everest crashes. Lots of new owners who've never had an SUV before and don't know how to handle one.

And, once again, don't pay any attention to that Honda salesperson. He just wants you to buy a bigger, more expensive car, so he can get a bigger commission.

**mbeige** · May 21st, 2008 12:42 PM

In a nutshell, if you're so concerned about crashworthiness, you're comparing the wrong cars. Get an MB, a Volvo, or a Subaru. I've heard that Subaru fares so much better than other cars of the same class, and of course we know that MB's and Volvos are dedicated to safety.

You can't really count on the statistics of car crash incidents back there because not all are recorded. And considering that presumably a good majority of cars sold over there are very stringent on safety features it's not uncommon to find severe damage to light collision impacts, but then again that could also be attributed to increased pedestrian safety (to easily crumple instead of remain resilient).

There is a fine line between pedestrian safety and crashworthiness. Manufacturers cannot have the best of both, and still remain cheap to fix on slow speed impacts. Speaking of which, some cars actually fare better during low speed impacts, than on high speed impacts. The more expensive cars usually fare better on both, than on just one. How slow is slow, and how fast is fast, you ask? Slow speed impacts usually are city speeds, around 40-60kph (25-40mph), and high speed impacts are usually highway speeds, which is around 80-100+kph (45-60+mph).

The solution is not to drive SUV's each time you go out, but to make cars more compatible with each other.

Take a look at You Tube and do a search on Fifth Gear crash tests, you'll see a lot of videos that describe the basic principles of vehicle accidents.

http://www.youtube.com/results?searc...h&search_type=

[ame="http://www.youtube.com/watch?v=k3ygYUYia9I"]YouTube - Fifth Gear Crash-test Volvo 940 estate vs Renault Modus[/ame]

[ame="http://www.youtube.com/watch?v=2fLg8eQaPyE"]YouTube - Fifth Gear laguna crash test[/ame]

[ame="http://www.youtube.com/watch?v=ovle-bkRVO8"]YouTube - Fifth Gear - Crash Testing[/ame]

[ame="http://www.youtube.com/watch?v=JXeKSDpFjlg"]YouTube - Fifth Gear - When an SUV rams a smaller car[/ame]

Just to list a few...

In the end, no matter how structurally sound a car can be designed, human tolerances can only withstand a certain amount of forces acting on the body. Beyond that, and you get internal organ damage. Even if the car fares well, the humans inside won't. In general, you'd want a car with more crumple zones that absorb the energy and transmit that throughout the vehicle (in smaller cars) or box that energy into the crumple zones (in larger cars that have enough space for crumple zones).

**niker** · May 21st, 2008 08:58 PM

Originally Posted by niky

What you're looking at here is how much attention manufacturers pay to crash integrity. Because compact cars must be sold in the European and US markets, where crash survivability versus large cars is important, they're over-engineered.

Most pick-ups and SUVs are based on old platforms. And they have lots of weight. No, not just the weight in front... everywhere! To keep from buckling, the crash structure of a pick-up must survive the impact and the forces of momentum applied to it from the weight of the vehicle trying to push it through the obstacle. As a consequence, they have to be designed much stronger to survive an impact... but they're not. Most people assume that the extra weight will save you, but that's just not universally applicable.

Look up the EuroNCAP website. The Honda Jazz scores higher than the old CR-V, but lower than the new one (simply, the new CR-V is a newer product). The new Civic scores much higher than the old CR-V, and is just one point behind the new CR-V in side impact tests. Both get four stars overall.

So... if your only compunction in upgrading to a new Civic or City is crash safety compared to your old CR-V, there's your answer. The Jazz is just as safe as the old CR-V, the Civic is much safer. And they're safer on the road because they're more maneuverable and have less of a chance of rolling over or going out of control than an old CR-V. The major reason you see these cars in crashes is because they're affordable, which means younger, dumber people drive them, people who've never driven a car before... period. That's why you see a lot of Fortuner and Everest crashes. Lots of new owners who've never had an SUV before and don't know how to handle one.

And, once again, don't pay any attention to that Honda salesperson. He just wants you to buy a bigger, more expensive car, so he can get a bigger commission.

After analyzing the EuroNCap for an hour. This is what I can say. The scores of say the frontal crash is taken from a level collision. The Jazz may have higher scores here. But when you are comparing a Jazz
and an older CRV. The higher body height and momentum of the CRV would penetrate into the Jazz deeper resulting in multi-damage. Since many cars
in the street are SUV. Then the CRV would be safer than the Jazz because in a CRV-Rav4 collision versus a Jazz-Rav4 collision. The latter would put the Jazz in shreds.

**mbeige** · May 22nd, 2008 03:29 AM

You're assuming four things, which may not always be the case.

1. You don't know if the CRV has crash structures that are built in to be more compatible with smaller cars, that results in less damage and a more crash compatible collision.

2. Even if many cars in the street are SUV's, that doesn't mean you will collide with one. There are also Jeepneys, trucks, other smaller cars, etc.

3. You can't vouch that the CRV would be safer than the Jazz in a collision with a Rav4. You're mixing three things there. How do you know how good the CRV fares against the Rav4? How do you know they will hit head on, instead of at an angle where most cars collide? How do you know if the angular impact will or will not cause the CRV to catch and roll over? If they roll over their arms will be flailing outside the vehicle if it doesn't have side airbags. They will bleed to death at the scene if that happens.

4. Without knowing the speed at the point of impact there's no way to tell what the chances of survival are.

**niker** · May 22nd, 2008 07:03 AM

Originally Posted by mbeige

You're assuming four things, which may not always be the case.

1. You don't know if the CRV has crash structures that are built in to be more compatible with smaller cars, that results in less damage and a more crash compatible collision.

2. Even if many cars in the street are SUV's, that doesn't mean you will collide with one. There are also Jeepneys, trucks, other smaller cars, etc.

3. You can't vouch that the CRV would be safer than the Jazz in a collision with a Rav4. You're mixing three things there. How do you know how good the CRV fares against the Rav4? How do you know they will hit head on, instead of at an angle where most cars collide? How do you know if the angular impact will or will not cause the CRV to catch and roll over? If they roll over their arms will be flailing outside the vehicle if it doesn't have side airbags. They will bleed to death at the scene if that happens.

4. Without knowing the speed at the point of impact there's no way to tell what the chances of survival are.

The CRV and all cars made of unibody design has horizontal beam or the bottom of the floorpan which is the strongest part of the car. So just imagine the floorpan of the 2004 CRV being higher than the Jazz, in fact, a foot above the stronger horizontal beam of the floorpan of the Jazz. This wouuld result in the CRV penetrating right into the Jazz body with major damage to it during collision of any angle. This analysis is why even though my 2004 CRV is high in fuel consumption, I can't just get rid of it and get a sedan because it has more superior crash safety preformance compared to any sedans.

I wonder if you know of web sites that show tests of collisions between sedans and SUV. If I am convinced by empirical data that the 2008 Civic is more superior than the 2004 CRV, then I'd sell the latter anytime. With fuel reaching 100 pesos / liter in december. Getting a light weight sedan may be a great idea as long as it stands a chance against the Suv, AUV, and other high rise vehicles that are now dominating the streets.

**niky** · May 22nd, 2008 04:44 PM

Originally Posted by niker

After analyzing the EuroNCap for an hour. This is what I can say. The scores of say the frontal crash is taken from a level collision. The Jazz may have higher scores here. But when you are comparing a Jazz
and an older CRV. The higher body height and momentum of the CRV would penetrate into the Jazz deeper resulting in multi-damage. Since many cars
in the street are SUV. Then the CRV would be safer than the Jazz because in a CRV-Rav4 collision versus a Jazz-Rav4 collision. The latter would put the Jazz in shreds.

Any force strong enough to get the crash cell of the CR-V all the way to the crash cell of the Jazz will destroy both crash cells. The CR-V is not a solid steel beam heading towards the Jazz. It's also a deformable crash structure on wheels that is being stressed upon impact. Consider that the Jazz is built of higher grade steel, any impact hard enough to destroy the Jazz's crash cell will destroy the CR-V's crash cell.

The force in the impact will not act only on the crash cells. The supporting structures, the subframes, will also deform. The CR-V does not have a solid ladder frame structure running underneath the cabin (which does nothing for crash protection... the body deforms and partially detaches from the ladder upon impact.). The floor of the CR-V is integrated into the passenger cell. The only way for that floor to go through the Jazz like a knife (as you're imagining) is for it to become detached from the passenger cell of the CR-V, in which case, the CR-V driver is also dead.

We're talking deformable sheets of metal here. Not solid I-beams of material. The closest you can come to this in a modern car is the front subframe, which has two solid members carrying the engine. This subframe is stiff, but also deforms on impact. And if, by some miracle, the CR-V's frontal structure clears OVER the Jazz's front subframe and crash structure (which it really won't...)... guess what? The CR-V will keep going over the top of the Jazz without deforming the passenger cell, and will flip over on the other side.

We're not talking about two blocks of butter colliding, you know... :hysterical:

It's completely unrealistic to assume that an SUV will go straight through a car's passenger cell, because to do so, the SUV will have to hit the car from an angle where it would be hitting the A-pillars head on, otherwise, it would ride completely or partially over the car, in which case the impact force would be dissipated. Maybe if the CR-V were falling off an overpass onto the Jazz, you would kill everyone inside... but I don't see anyone testing for that...

The only way to realistically get a direct impact with the passenger cell would be to drive a car straight into the rear end of a parked truck without a rear bumper. And even then, people have walked away from such impacts. the crash cell slides under the truck and lifts it up partially before collapsing... cushioning the passengers from the impact.

If you really want to keep your CR-V, go ahead. The CR-V probably has an extra foot of water-fording capability over the Jazz (though if the water gets to your computer box, it's still futzed... we've got two drowned CR-Vs to prove it) and it has more space... but don't base your decision on problems that don't actually exist.

**mbeige** · May 22nd, 2008 05:27 PM

The CRV and all cars made of unibody design has horizontal beam or the bottom of the floorpan which is the strongest part of the car. So just imagine the floorpan of the 2004 CRV being higher than the Jazz, in fact, a foot above the stronger horizontal beam of the floorpan of the Jazz. This wouuld result in the CRV penetrating right into the Jazz body with major damage to it during collision of any angle.

Maybe if the two cars did not have any doors. But penetrating right into the Jazz body? That's why there are side impact beams and reinforced dashboard bulkheads in order to prevent intrusion in a side impact. There is no way to tell which of the two has stiffer (insert part) components because each is designed individually, and not in comparison with another chassis or vehicle.

This analysis is why even though my 2004 CRV is high in fuel consumption, I can't just get rid of it and get a sedan because it has more superior crash safety preformance compared to any sedans.

Take a look at the EuroNCAP for Honda - most of their cars are 4-star cars in frontal collision tests. How can the CRV be superior to other cars? You're not saying that the CRV is the "topnotch" of the bunch, are you?

Take a look at these links

http://www.whnet.com/4x4/crashes.html

http://www.detnews.com/specialreports/2002/nhtsa/

I wonder if you know of web sites that show tests of collisions between sedans and SUV. If I am convinced by empirical data that the 2008 Civic is more superior than the 2004 CRV, then I'd sell the latter anytime. With fuel reaching 100 pesos / liter in december. Getting a light weight sedan may be a great idea as long as it stands a chance against the Suv, AUV, and other high rise vehicles that are now dominating the streets.

Did you even bother to check the videos I posted? There were several tests showing SUV versus car collisions and why the compatibility issue is such an issue. Here's a good link

http://www.whnet.com/4x4/accident_corolla.html

I hate to say this but Niky is right - you're creating a problem that does not exist. Your dilemma is whether to choose the newer Civic or your current CRV, right? Against what? SUV's? AUV's?

I just watched a video and one quote that I got from it that may help clear your mind is that, "There will always be a bigger guy" - what that means is there will always be something more dangerous than you think, regardless of what you do. The best thing you can do is to do your homework, pick a car, drive safely, and keep an eye out. Why will we convince you to get either car - we don't know what your priorities are. In the end it'll ultimately be your decision.

No one car is perfect. Mind you, small cars are getting better and better in terms of crashworthiness. That proves that bigger isn't necessarily better, but it helps to have a car that has ample space to crumple. Along that line, more modern cars are made of high strength materials that can withstand greater forces than they could years ago, so manufacturers can create smaller yet tougher cars. However, most of the crash tests that are conducted are done at typical low speed impacts (city driving). High speed crash tests are often not conducted. Some cars can fare better in low speed impacts, while others at high speed ones, and even some at both.

Again, I reiterate, take a look at the videos. More notable, these ones:

[ame="http://youtube.com/watch?v=k3ygYUYia9I"]YouTube - Fifth Gear Crash-test Volvo 940 estate vs Renault Modus[/ame]

[ame="http://youtube.com/watch?v=JXeKSDpFjlg"]YouTube - Fifth Gear - When an SUV rams a smaller car[/ame]

And this one

[ame="http://youtube.com/watch?v=GEBC9PbjPv4"]YouTube - Fifth Gear Crash Test Renault Espace vs Land Rover Discovery[/ame]

**niker** · May 22nd, 2008 05:43 PM

...........

**mbeige** · May 22nd, 2008 06:01 PM

Hope there are videos out there of CRV-like vehicle colliding with Jazz-like vehicle.

Watch the second video I posted.

The larger momentum and larger body surface area of the CRV would translate to more superior impact points such that the Jazz passengers would suffer more damage than the occupants of the CRV. Agree?

Depends. Are both traveling at the same rate of speed? Is it a head-on collision, or a side impact? Angled impacts perhaps? Full frontal or 40% offset front impact?

Let's just settle on this basic point muna that the CRV is safer than the Jazz in a head-on collision? Disagree?

Full frontal or 40% offset collision?

Full frontal, maybe so with the frame of the CRV overriding the safety features of the Jazz. In a 40% offset collision that may be a different story, since the same amount of energy is focused on each side of the crumple zone, thereby increasing the load on each front chassis rail.

Then you have to consider: Will the doors open after the collision? Is there cabin intrusion? Did the pedals move backwards? Did the steering column collapse as designed? Did any of the windows break, resulting in glass shards? Even if the airbag deployed, were they sufficient to protect the passengers from hitting their face on the steering wheel?

**Galactus** · May 22nd, 2008 06:29 PM

Honestly, I don't think the TS is in the market for a new car. He simply wants to stir up a debate, judging from his other thread at Honda Cars Talk. So in that sense, "enlightening" him will be an exercise in futility, he seems dead set on his views and will defend it to death.

Skip this one, guys. Move on to another topic.