Compact cars unsafe?

[theveed]

Bike nalang tayo lahat hehehe...

[theveed]

Can't beat this though...

[ame="http://youtube.com/watch?v=F06LjugtIUo"]YouTube - New Chinese Car Crash Test Disaster - 2007 Brilliance BS6[/ame]

Hehhe

[theveed]

Oh, I guess we also just presented why cars are getting bigger, heavier and more expensive, these crash tests and research can't cost peanuts....

[theveed]

Just read Niky's post... Totally agree...

You can give me a sports car, but if my family is on-board, I'm extra cautious and I rarely drive over 80... Give me a dinky 1.3 alone with an open road during a bright day, I wouldn't even think twice hitting above 100.

It'd be best for crowded places to not have cars that can go over 50kph hehehhe

[wren]

tsaka they're only talking about passive safety, no mention of active safety. smaller cars are more maneuverable, so you are more likely to avoid an accident than the plodding big cars/SUV.

[docpete]

sabi nang isang mayari ng picanto..di daw siya rinerespeto ng mga tricycle sa loob ng bayan or sa highway baka lang dahil babae siya

[mbeige]

tsaka they're only talking about passive safety, no mention of active safety. smaller cars are more maneuverable, so you are more likely to avoid an accident than the plodding big cars/SUV.

Right, but passive safety is when you never really saw it coming and it just hit you, which I think is more important. Most cars today are pretty agile, which is a good thing in avoiding accidents altogether. Even the SUVs are becoming more agile than they were back in the day, though there are still some that are lagging behind.

The point of the whole thread is that compact cars are safe these days, if only other cars on the road were also compacts. But the reality is that there are bigger, heavier cars. The crash compatibility issue will always be an issue because of height differences between a compact car and, at least, a compact SUV such as the RAV4, CRV, Escape, etc. Even scarier is that I don't see a lot of crash tests done on vans or minivans such as the Starex that is so popular there or the other counterparts by other makes.

Also consider that even if the car's cabin remained intact, the lateral forces affecting the passengers such as the one seen in the Smart car video will be too much and your internal organs will probably get injured even if you seem physically fine from the outside.

[niky]

A big car, with lots of inertial energy, will have a harder time shedding that energy on impact... which is why, until recently, some big SUVs have had horrible crash scores, because that kinetic energy ripped apart crash structures and supports.

If you're in a small car and properly belted, you can definitely survive the impact deceleration. Look at F1 cars... 350 km/h and straight into a wall... but the drivers survive due to protection from the crash structure and proper restraint... not due to the car's mass absorbing energy. Of course, it takes carbon fiber to keep them alive, but then, that's not the point... the point is that as long as the driver is properly restrained, he doesn't absorb the forces of the impact... it passes through him on the way to the back of the car.

If safety agencies mandated four point or five point harnesses, I'd be all for it... it would reduce fatalities by a hell of a lot.

Small cars are approaching the point where crash structures are getting pretty good. A Honda Jazz is safer than an early 90's Accord. And look at cars like the Jetta (mentioned in-article), or the Ford Focus... I feel the Focus is discriminated against in the PTCC... with the amount of crash structure, it shouldn't need a roll-cage... that's just added weight!

Proof of the stiffness of this crash structure? The handling... the excessively rigid bodyshell of the Ford gives it great handling for its weight, compared to the Civics it's running against. The Jazz is another new car with exceptional handling, despite its relatively crude suspension... thanks to a stiff structure.

The problem with small cars in some crashes is that they're built to absorb a certain amount of force by use of crumple zones. We need these crumple zones to absorb kinetic energy at the point of impact because people don't always wear their seatbelts properly. By crumpling up, the car absorbs impact and transmits less force to occupants who are not properly restrained.

If you restrain occupants in the proper manner (as in a racing vehicle), you could make the crumple zones stiffer (without incurring a weight penalty, you're just changing steel grades, not the amount of steel), transmit the energy throughout the entire car more easily (and if you're strapped in tightly, it'll just pass through you) and avoid fatalities in harder crashes.

[mbeige]

A big car, with lots of inertial energy, will have a harder time shedding that energy on impact... which is why, until recently, some big SUVs have had horrible crash scores, because that kinetic energy ripped apart crash structures and supports.

If you're in a small car and properly belted, you can definitely survive the impact deceleration. Look at F1 cars... 350 km/h and straight into a wall... but the drivers survive due to protection from the crash structure and proper restraint... not due to the car's mass absorbing energy. Of course, it takes carbon fiber to keep them alive, but then, that's not the point... the point is that as long as the driver is properly restrained, he doesn't absorb the forces of the impact... it passes through him on the way to the back of the car.

F1 car drivers are trained for this kind of thing, normal drivers are not so the chance of survival for normal drivers would be much lower. Also you must consider realistic events. Not everybody will be properly restrained, some will be too close to the steering wheel, for example, because not everybody knows the consequences. These kinds of things must be considered when producing a passenger car compared to an F1 race car.

If safety agencies mandated four point or five point harnesses, I'd be all for it... it would reduce fatalities by a hell of a lot.

The problem with this is that the harness must be anchored to a point far behind the driver/passengers like on the rear seat anchor points. This is because in an accident when the harness is anchored on the floor right behind the front seats, it will actually serve as a trap rather than a harness. It will then make multiple-passenger vehicles such as vans, 4-door sedans, wagons, SUV's, etc impractical.

Small cars are approaching the point where crash structures are getting pretty good. A Honda Jazz is safer than an early 90's Accord. And look at cars like the Jetta (mentioned in-article), or the Ford Focus... I feel the Focus is discriminated against in the PTCC... with the amount of crash structure, it shouldn't need a roll-cage... that's just added weight!

Proof of the stiffness of this crash structure? The handling... the excessively rigid bodyshell of the Ford gives it great handling for its weight, compared to the Civics it's running against. The Jazz is another new car with exceptional handling, despite its relatively crude suspension... thanks to a stiff structure.

A stiff structure may be good for the cabin but the crumple zones must be staggered so that the kinetic energy will be absorbed in stages. See the video on the car that was in an accident, repaired, and crashed against a Focus that had no prior accidents. The salvaged title car fared poorer and the occupant could have been killed because of this. The structures may both be stiff but the manner in which the kinetic energy is absorbed is another matter altogether. Some cars probably have crumple zones but the way they're engineered can not be observed just from the handling and performance of the car.

The problem with small cars in some crashes is that they're built to absorb a certain amount of force by use of crumple zones. We need these crumple zones to absorb kinetic energy at the point of impact because people don't always wear their seatbelts properly. By crumpling up, the car absorbs impact and transmits less force to occupants who are not properly restrained.

The problem with small cars is that they do not have large enough crumple zones or that the crumple zones are too small so they have to be reinforced, which adds weight; therefore they have to shed weight elsewhere.

If you restrain occupants in the proper manner (as in a racing vehicle), you could make the crumple zones stiffer (without incurring a weight penalty, you're just changing steel grades, not the amount of steel), transmit the energy throughout the entire car more easily (and if you're strapped in tightly, it'll just pass through you) and avoid fatalities in harder crashes.

Look at the Smart car crash test. The crumple zones were stiff enough and the cabin looked intact except for a "nasty kink" on the A pillar. However I'm pretty sure the occupants would have experienced severe G-forces that may also be fatal. You can be properly restrained but in a high speed crash, if there are really small crumple zones or they're not designed properly (crumple too early as mentioned in one of the videos) the passengers will suffer injuries and possibly death.

These compact cars are great for city driving but when it comes to high speed driving I feel much more comfortable in our larger cars than in the compact cars.

Compact cars are safe enough for "average" condition or "normal" accidents like city driving accidents and the like but the risk of colliding with any vehicle that has a higher frame, or worse, a stiffer body that will take advantage of the compact car's softer shell, is highly possible also. What I'm saying is that in their own perspective, they are truly safe cars. They are light, nimble and agile but when they collide with a much larger car with stiffer crumple zones, they will be thrown around more and will absorb more energy than they're designed for.

I'm not disagreeing with you Niky, I see your point my friend. All I'm saying is that you also have to consider other vehicles with different designs. I also agree with you that proper restraint is key, hence the mandatory use of seatbelts, headrests, airbags, etc when and where you need them. Most of the time, on average accidents where city driving is involved, the cars usually fare well enough that the occupants survive. But when the crash compatibility issue comes up and happens, chances are the larger and heavier vehicle usually overrides the smaller car's safety features.

It looks like we'll have a good discussion here.

[niky]

Nah... let's just flame!

As for F1 drivers, the only additional training that means anything in an out-of-control crash is the presence of mind to take their hands off the wheel to prevent wrist and finger injury. Restraint is the key.

As for harnesses, well, the most effective harnesses are anchored to strong points far back in the cabin, but it's possible to design in-seat harnesses that are strong enough.

RE: Smart car: Whether or not the pillar collapses is incidental. What's important is the speed of the collapse.

RE: Focus: well, it's a given that a crashed car that is improperly repaired will not be safe. That goes for any type of car, whether big or small.

RE: The size of crumple zones. The less mass on the vehicle, the less force a crumple zone needs to absorb. Of course, modern design language conspires against making bigger crumple zones, but I'd suspect if manufacturers would give cars their noses back, everything nowadays would be 5-star.

Unfortunately, what you said about small car versus big object = true. But a concerted drive to decrease curb weights would make things safer for all motorists, as long as the decrease in weight is in the right area.

Yes, I do feel safer in heavier cars... they're often steadier at high speeds, and can absorb hard impacts. But look at Princess Diana's death. That was in a relatively heavy, very "safe" car. Anything can be unsafe in the wrong conditions. A Honda Jazz is 1000 times safer than a Chinese SUV... by smart use of weight and design... and driving one, I can feel the solidity... (although it does sound like a tin can at times... :hysterical: )

A heavier car can be made nimble, but in treacherous conditions, they are still at the mercy of momentum... while tire technology has made it safer for SUV drivers in recent years, it still can't make up for all conditions. Also note: heavier compact cars which are "safe" are often made by luxury manufacturers, who charge more and can spend more on materials and crash structure. Sure, they're heavy, but only a portion of that weight is crash structure. Stripped of non-essential insulation, a Ford Focus (sorry for overusing this one... hehehe) can lose about 50 kilos.

It's possible to design small cars that are very safe and still not so heavy. The only problem is designing large cars that are safe for small cars to crash into...