Compact cars unsafe?

[mbeige]

Alright let's just flame

RE: Smart car: The rate of collapse is so great because it went from 70mph to 0mph in a fraction of a second and with the relatively small crumple zone the car made it intact but if there was somebody or at least a dummy I'm sure it would have registered a huge force on its body.

RE: Size of crumple zones: You're right about the less the mass is on a vehicle, the less energy it has to absorb. But when it comes to two vehicle collisions and not just a vehicle vs a non-moving object (fixed or not) the other vehicle will also send its kinetic energy into the other vehicle. This actually makes those insurance safety rating tests provide half the story. What if another car is traveling towards you at the same speed but head on? Of course the speed is doubled. So regardless of the mass of the vehicle in subject, if the other vehicle is much heavier, the vehicle in subject will either not be able to withstand the kinetic energy of the other vehicle in addition to its own kinetic energy, or at least marginally withstand it but with possible injuries. Hence, it will work twice as much to prevent occupant injury/death. This makes it even harder when offset crashes occur because all or most of the kinetic energy is targeted to only one side of the vehicle frame so it absorbs twice as much energy from each car. That's why offset crashes are the most severe head-on collisions, and full-frontal impacts come in second.

RE: Princess Di's death: She was not wearing her seatbelt. Her bodyguard in the front passenger seat, I believe, was wearing his, so he survived. This is a common topic discussed in Benz forums. Had she been in one, even if the vehicle collided with an infinite mass object (the tunnel posts/dividers) the vehicle would still have saved her because she was in the rear seat and was farther away from the point of impact than the front passengers.

RE: Vehicle mass/weight: True, a heavier car can be made nimble and lighter cars can be more agile at extremes. But cars these days are designed with good handling properties especially with the advent of electronic stability control systems, ABS, and the like to maintain control and avoid accidents. I cannot comment on what portion of heavy cars is dedicated to crash structure, but I can vouch that for those luxury cars a lot of the extra weight is due to added equipment, electronics, sound insulation/deadening, etc that most non luxury cars do without. Like you said, manufacturers can opt to use a different grade of steel to make crash structures stiffer, and in these luxury cars where a bonnet is still a bonnet (and not just half of one) I'm pretty sure there's ample room for advanced crumple zones. So not all heavy cars are heavy due to the crumple zones, but it's always good to have a heavy car yet one that can still get out of harm's way in an emergency.

RE: Harnesses: Manufacturers who install pre-tensioners on self-retracting belts (in accidents) will have to install double or maybe even triple the number of electronics in these cars and have to use more space, so car prices will definitely be higher. The 3-point seatbelt these days are pretty good for what they are already. In the current S-class, PRE-SAFE actually triggers near or at the point of collision to adjust the driver to the safest crash position by inflating the seat bolsters, tightening the seatbelts, closing the sunroof, adjusting the seats, and braking the car properly to minimize the kinetic forces that could act on the passengers. Like you said restraint is key. Restraint position is even better because some people (like my stubborn brother in law) always drives gangsta style with the seatbacks nearly fully reclined. In that position he has a really high chance of sliding forward in an accident despite wearing his seatbelt.

I've felt safe in our Honda Jazz when I drove it there for 2 months, but something else was lacking that did not inspire that confidence level whenever I'm driving on the highway. I guess its lightness and lack of sound insulation made it feel nervous and jittery at speed. Driver confidence is another critical safety issue that not a lot of manufacturers focus on. There was a test done that showed the S-class provided the lowest heart rate while driving compared to the Audi A8 I think and the BMW 7.

RE: F1 driver health: Their physical condition is still of debate of whether they are considered athletes or not. I've read somewhere that they lose a good amount of water after a race so their rigorous training is just as crucial. On the other hand, normal passenger cars need not to be pushed to the limit so average condition drivers (sedentary people too) can still drive them without as great a risk as those F1 drivers face. Like you said, they need to have the presence of mind to do as they were trained to do. But for normal drivers, I'm pretty sure a good number of people who drive don't even know what happened until they regained consciousness again right after an accident. This is what happened to my friend in the Accord, it happened so fast. This is why passive safety is of prime concern and not just active safety, because he never saw it coming. Whereas in a race, you can still predict to some extent what can happen, because the drivers are trained to face these kinds of things.

[oldblue]

smart car? pang nabangga eto hindi ka mag-crumple tatalbog ka parang bola ng bilyar kung san tamaan

[VtEC]

kahit ano pang technical explanation about compact cars, kakatakot padin sila.safe padin kahit papano yong bigger cars.sa head collision mas lalo na.naiimagine ko agad after ng impact sa liit ng mga compact cars baka compartment nalang matira e.anyways, pag oras munang mamatay regardless na yan kahit ano pa o san kapa nakasakay.pero takot padin akong magsasakay sa mga compact nayan, psychological.specially sa smart cars (for one or for two)parehas din

[afrasay]

I think safety starts with the driver itself.

[VtEC]

yah you are right, but the problem arises when the other driver is reckless and hits you hard on a compact car.from there, you will see the big difference between a compact and say a sedan lalo na sa SUV

[aku]

dun sa video with the smart, i don't think there's anything that could have been done given those conditions. any would-be passengers would have died because of massive deceleration forces, since the car was going so fast, not because of any design faults.

[Flagg]

Galing ng Smart Car! Buo pa!

[Dr.Kamiya]

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...

Actually a good part of what keeps the drivers safe is the ability of carbon fiber to absorb huge amounts of energy safely. Unlike steel or aluminum which would buckle on impact, CF disintegrates as it absorbs energy. You should see the nosecone crash tests, they pile a weight behind a simulated nosecone part, ram it into piece of metal at speed and measure the energy loss. Part of the nose disintegrates in the process, and in doing so absorbs a good deal of energy without turning into dangerous, sharp, pointy bits.

I'd go out on a limb and say CF is probably the best material to create a car with, it's very light, very strong and does exceedingly well in a crash. Of course it doesn't help that it's also very expensive.

[jpdm]

--delikado compact cars lalo dito sa Pinas. Ako nung naka daihatsu charade ako, kahit anong ingat ko sa pagmamaneho, 3 or 4 na beses na ako na-sideswipe ng mga bus at truck sa Cavite. nag-uunahan o nagmamadali lagi kasi yung mga pampasaherong bus. Tapos yung truck walang paki pag nakita kasalubong o katabi niya maliit na sasakyan. Bastusan talaga.

dapat sa pinas pag naka-compact car ka, dapat itatakbo mo lang sa mga secondary road o city, municipal roads at wag highway o expressway. Kung di maiwasan, you should equip you compact car with a bazooka o anti-tank weapon. Di kana sasagiin

[aku]

wait lang, i'm getting a bit confused... when we say "compact", we are talking about corolla/civic-sized cars, right?

[empy]

i think we need to go back to one of the central assumptions of the article and tests: all else being equal.

an idiot behind the wheel is an idiot no matter what he drives. if more idiots drive SUV's and skew the accident stats, you have to take that out of the equation.

ditto driver skills. it makes me laugh when someone says "small cars are more maneuverable and can avoid accidents". Lexus even had a campaign for this. the average driver is too unskilled or too distracted to avoid accidents even if his car handled like a Caterham. take that out of the equation.

with all those variables out of the equation, then the cold hard facts will be reflected in the crash tests. and compact cars simply don't fare as well. as mbeige said, laws of physics.


now - put all the other variables back in. say you're a safe, mature, skilled defensive driver. your safety factor will be sky high no matter what car we put you in.

i like to think i am a safe driver. but since i would like to reduce my death/injury risk from small to really, really small, i buy the safest cars anyway, and i make sure all occupants are properly restrained. one of the main factors in me buying BMW and VW are the excellent safety and crash ratings of those models. i will do most of the work in avoiding accidents every day, but when i fail, i expect my car to take over the work in protecting my family and i.

Volkswagens, in general, he says, "tend to be safe, but they are heavier and get lower fuel economy. If you improve safety, you make a vehicle heavier, at least with today's technology."

Jetta, a compact, weighs more than 3,200 pounds, the same as a midsize car and about 500 pounds more than a typical compact. The weight of its safety hardware and extra-robust structure drags Jetta's mileage per gallon into the mid-20s in combined city-highway driving, same as a midsize car and about 5 mpg less than a typical compact. And Jetta's starting price of $17,000 is about $2,000 more than other popular compacts.

exactly. i personally would pay $2000 more if it improved my/my family's survivability, even in a small way.

[scharnhorst]

wait lang, i'm getting a bit confused... when we say "compact", we are talking about corolla/civic-sized cars, right?

smaller. think getz, alto, etc...

mas buo pa yung smartcar kesa dun sa F150 crashtest na nakita ko

[niky]

Nope. Compact refers to Corolla-class vehicles.

Weird, huh? Here, cars like the Corolla, Civic and Focus, at 1100 - 1300 kgs, aren't at a huge safety disadvantage versus Japanese box vans, Asian Utility Vehicles and Jeepneys, which often weigh just 1600-1900 kgs.

In the US, they're considered dangerously small as compared to 2 - 4 ton SUVs roaming the streets.

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*mbeige: well played. I really can't dispute the car versus car scenario. Physics... the car with more momentum will transmit momentum to the other car in a crash... and the car with more momentum is usually the bigger one. One note on offset crashes though... they're actually better, as the force is not transmitted directly to the vehicle. The decelerative force transferred to the vehicle is redirected laterally, and the vehicle doesn't absorb so much of the impact. But yeah, if the car isn't well made, that impact can still cause more deformation by causing twice the load on the side crash structure.

I still don't agree on buying a heavier car just in case it has more crumple zone/crash structure... you still have to consider how well it is made (as in the case of domestic SUVs)... but I'll have concede the all else being equal points...

Caught me on Diana, too.

RE: relaxation and driving safety... good point... as long as the driver is not too relaxed... just calm.

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*Dr. Kamiya: if only CF weren't so labor-intensive to make... *sigh*, maybe someday someone will figure out how to make cheap CF weave... maybe a bamboo weave mixed with a strong, non-toxic epoxy would be of similar strenght? ;)

[mbeige]

*mbeige: well played. I really can't dispute the car versus car scenario. Physics... the car with more momentum will transmit momentum to the other car in a crash... and the car with more momentum is usually the bigger one. One note on offset crashes though... they're actually better, as the force is not transmitted directly to the vehicle. The decelerative force transferred to the vehicle is redirected laterally, and the vehicle doesn't absorb so much of the impact. But yeah, if the car isn't well made, that impact can still cause more deformation by causing twice the load on the side crash structure.

I still don't agree on buying a heavier car just in case it has more crumple zone/crash structure... you still have to consider how well it is made (as in the case of domestic SUVs)... but I'll have concede the all else being equal points...

Caught me on Diana, too.

RE: relaxation and driving safety... good point... as long as the driver is not too relaxed... just calm.

RE: Offset crashes: I think you mean side impact crashes that throw the cars into circles right after impact. The head on but 40% offset crashes actually put twice as much energy on one of the frontal crash "forks" and that's what makes it so deadly and puts so much strain on the crash structures designed on the cars.

But I know what you mean with not 100% of the force is transmitted on the other moving body. That's actually why some people say they prefer not to wear seatbelts because they'd rather be thrown out of the vehicle and land "safely" kuno. Of course we all know this is a fluke and they'd probably die from hitting the ground or worse, being run over by other vehicles.

Personally though I'd rather have the cars collide and hit each other so both cars will deform as planned, rather than throw them elsewhere out of control. But we can't always control things.

Hey I'm not trying to bat against you, just pointing out the objective views. I've had my fair share of crash test experiments Remember those Lego models I used to make? I also crashed them and studied how they reacted. Needless to say they pretty much turned out to crumple similarly. Well ok this Fit did poorly but that's because this was the first design which I've since upgraded and finalized



But we're getting off topic now

By the way here's a good link about subcompact cars, and the corresponding compact cars.

[scharnhorst]

hahahaha * the lego crash test

Subcompacts pala yung mga binanggit ko.

then again, in the philippines, we have all these carelessly driven buses to compensate for the scarcity of big SUVs.

and if they're worried about compacts crashing into SUVs, here we've seen motorcycles go up against trucks and buses.

[niky]

*mbeige: no worries... this debate is just a thought experiment for me... as we're trying to analyze why compact cars are perceived as less safe, and how much of that is truth and how much is perception.

There's always three sides... yours, mine and the truth. The point of a debate is to see which one of us the truth agrees with. Sadly, for me, it looks like it's leaning towards yours... :lol:

Hey, it's not like we're debating Evolution or Iraq... :hysterical:

[pup2]

Maybe God made more agile small cars with good defensive drivers that way to avoid big accidents. So that if your car is neither small nor are you good or defensive, you should get a somewhat bigger one.

[mbeige]

*mbeige: no worries... this debate is just a thought experiment for me... as we're trying to analyze why compact cars are perceived as less safe, and how much of that is truth and how much is perception.

There's always three sides... yours, mine and the truth. The point of a debate is to see which one of us the truth agrees with. Sadly, for me, it looks like it's leaning towards yours... :lol:

Well, you had a very good point about different drivers and conditions, but I focused (pun intended) more on the physics

[hominid]

--delikado compact cars lalo dito sa Pinas. Ako nung naka daihatsu charade ako, kahit anong ingat ko sa pagmamaneho, 3 or 4 na beses na ako na-sideswipe ng mga bus at truck sa Cavite. nag-uunahan o nagmamadali lagi kasi yung mga pampasaherong bus. Tapos yung truck walang paki pag nakita kasalubong o katabi niya maliit na sasakyan. Bastusan talaga.

Agree ako d2. Ako nga, ginitgit dahil me kasalubong daw na motor un truck na omovertake sakin. Biro mo, sa motor natakot, sa Getz ko hindi. Langya...

Actually depende sa car kung safe cya o hindi, kaso hindi nirerespeto mga maliliit na sasakyan sa daan ng mga trucks and buses.

D2 sana natin medyo i-shift ang topic na ito.

Kung ang mga tricycle non-stop singit, ang mga trucks/buses, non-stop sugod. Gaya dati d2 nun fiesta. Me mga visitors na naka tourist bus. Pinag-gigitgit mga stall ng sidewalk vendors. Impossible naman na d nya kita sa side mirror un. Feeling ogag lang talaga.

Kung mga SUVs o PUJs, sa tingin ko ayus naman pakisama nila sakin. Madalas rin akong nahihintuan at tinatanong magkano daw sasakyan ko. OT na.

[herbolero]

--delikado compact cars lalo dito sa Pinas. Ako nung naka daihatsu charade ako, kahit anong ingat ko sa pagmamaneho, 3 or 4 na beses na ako na-sideswipe ng mga bus at truck sa Cavite. nag-uunahan o nagmamadali lagi kasi yung mga pampasaherong bus. Tapos yung truck walang paki pag nakita kasalubong o katabi niya maliit na sasakyan. Bastusan talaga.

dapat sa pinas pag naka-compact car ka, dapat itatakbo mo lang sa mga secondary road o city, municipal roads at wag highway o expressway. Kung di maiwasan, you should equip you compact car with a bazooka o anti-tank weapon. Di kana sasagiin

I currently have a Daihatsu Mira(NORKIS VERSION), actually it is my second unit. The first one was badly damaged, four days after i got it from the dealer, by a 16-wheeler driven by a sleepy driver. My car was dragged (with me inside) almost 20 meters before the driver could even realize that he hit something. The insurance people decided to replace it because repairing it would probably cost more. I have to admit that there is really a factor with size when you consider safety. I drive more carefully now, making sure that i let big trucks pass especially when cornering. Looking on the bright side, i came out of a close call without a scratch.