What do 5-star ratings really mean?
When manufacturers get a 5-star crash rating for one of their models, the klieg lights and publicity klaxon get thorough workouts. Those tiny ten-sided polygons have gotten to mean so much to consumers that it's not unusual for a carmaker to drop a few hundred large on prime time commercial space and 60-point text to convey the message. Well, not to deflate anyone's... airbag... but Airbag Solutions has broken down the test methodology and what the results mean in real-world cases. It in no way demeans the quality of the rating system or the work done by the National Highway Traffic Safety Administration, as well as similar tests performed by the Insurance Institute for Highway Safety, but it does show that ultimately the ratings apply to a narrower set of circumstances than one might have thought. For instance, crash test dummies replicate effects only for adults -- babies, kids, and teenagers don't count. If you're in a crash at more than 40 mph, or if you hit a car with a weight differential of more than 250 lbs, the rating scale doesn't apply. One would assume that a 5-star car at 38 mph would still be better in a crash at 70 mph than a 3-star car, but there's a lot of gray area around the well-defined boundaries of the protocols. Click the 'Read' link to get the full story.
[Source: Airbag Solutions]
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Reader Comments (Page 1 of 2)
Greg 10:43PM (7/11/2007)
So does this mean the Brilliance from China is now the safest car on the road?????
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Rambo 12:31AM (7/12/2007)
SMALLER CARS ARE NOT AS SAFE! I've told many people this before. The ratings are based on vehicles of similar size. That means a 5 star compact is not as safe as a 5 star fullsized car. Bigger is better.
Gil 3:30AM (7/12/2007)
Right Rambo. Bigger is better! Let's all drive dumptrucks
Bigger is not better
seoultrain 10:52PM (7/11/2007)
from site:
2. Crash dummies only simulate full size adults, not teens, not children, not infants. Aren’t teenagers, children and infants passengers too? Why don’t they count in the ‘rating’ system?The crash dummies are wearing seat belts in all cases, front and rear seats...(everyone in vehicles always wears their seat belts, don’t they?).
just throwing this out there, but I've seen plenty of crash tests with kids in the back seat
As for the seat belt thing, it doesn't take a crash test to find out what happens to an unbelted passenger in a major crash. Although I've seen videos of those too. Fifth Gear just did one with a stretch limo.
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seoultrain 10:58PM (7/11/2007)
hate to reply to my own post, but I just finished reading this. I started out thinking it'd be nice to read a logical, well-written analysis of crash tests ("in no way demeans the quality of the ratings system" led me to think this). However, it seems like Brilliance paid a 6th grader to write up the site. There's holes in nearly every statement, and comes off as way too opinionated and preachy to be taken seriously. Shame..
Jay 2:40AM (7/12/2007)
Yea I've seen them too but I think he meant that the star rating apply to Adults only since they used the data from the adult to make the star grade which means the star system would differ for a teen or infant.
Peter 8:06AM (7/12/2007)
Why account for idiots not buckling up? It's simply natural selection at work.
omar 8:39AM (7/12/2007)
Crash test dummies do not only simulate adults. Volvo Car Corp Safety Center has crash test dummies for different sied adults that could be regarded as teens. They also have test dummies of children and infants for various seat configurations, and even the world first pregnant crash test dummy. you should have checked out these before you made that statement. Volvo and Mercedes are at the forefront on safety technologies that is why their vehicles rake in the top ratings. The entire volvo lineup has top score ratings in their select premium vehicle classes.
Volvo. For Life.
rooster 12:43PM (7/12/2007)
This has to be one of the biggest, boldest, most thought provoking studies in history. I mean, to actually assert that the basic laws of physics applies to automobiles and humans. That's groundbreaking stuff. I mean, isn't it astounding to learn that crashing your five star, 3,000 lb car into a 6,000 lb, four star truck or SUV will probably leave you in the hospital while the guy with the bigger car walks away? They crash cars into fixed barriers, so the only energy is that from the car. Not very representative of real world circumstances. Here's a use for crash test ratings. Multiply the square root of the number of stars times curb weight if you want to compare vehicles. (The square root is a nod to the basic laws of conservation of momentum M=1/2*M*V^2.)
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seoultrain 2:03PM (7/12/2007)
fixed barriers are not representative of real-world circumstances? You've never heard of cars running into telephone poles, trees, houses, etc? It's at least representative of some real-world conditions.
You are definitely correct about the weight thing. It's become stylish to say that heavier cars are not safer, but the correct statement is that heavier cars are not _always_ safer. A heavier car will undergo the same change in momentum as a lighter one (assuming car-to-car collision), but the heavier one will experience less acceleration. Think of the extreme being a bug splattering on a windshield. Same momentum change, but big difference between the car and the bug's outcome. That said, smaller cars have improved so much that they overcome the weight disadvantage.
to nitpick, your equation is for kinetic energy (KE=[mv^2]/2). Momentum is simply p=mv.
phil 12:20AM (7/12/2007)
"6) If you happen to be driving a “5 Star Rated” vehicle at 32 mph, hit a car head-on exactly like yours and are
wearing your seat belt, according to the ratings you still have a 1 in 10 chance of being killed!
7) Lastly, if you are driving a “1 Star Rated” vehicle (I don’t know of any) and are in the same accident, you still have a 50-50 chance of surviving. "
"50-50"? I like those odds! Good thing I didn't spend that extra 100 dollars on the safer car. PHEW!
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Brad 1:09AM (7/12/2007)
I don't put much belief into crash ratings. You can get killed just as easily in a 5 star rated vehicle as one with lower ratings. Crashes are like snowflakes, no two are hardly alike.
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Chris 1:25AM (7/12/2007)
I agree, no 2 crashes are alike, but I'd still rather take my chances in a car thats established to be safe. Having been a volunteer ems for 15 years, I'd most certainly rather be in a Mercedes, Volvo, or BMW than in a Neon or Corolla for ANY type of accident severe or not.
seoultrain 2:30AM (7/12/2007)
I agree w/ Chris. Crash tests are scientific and standardized, and although they may not replicate all real-life crashes, they give an indication of crash performance in the real world. When a part of a crash structure fails in testing, it is more likely to fail in real life.
Just because an experiment is not 100% indicative of real life doesn't mean it has no credibility. Especially when there is no better alternative information.
Rod Howell 3:51AM (7/12/2007)
While I agree there are deficiencies in crash tests (see below), Let's debunk some of this article.
1. "The tests are conducted at speeds of 35 to 38.5 mph. Wait a minute.....35-38.5 mph? Who drives 35-38.5 mph. when the rest of the world is traveling at 45-75 mph? The government safety ratings do not cover anything over 38.5 mph"
While it's true we travel faster than the crash tests, most people brake before getting into an accident. Sure there are occasions when people don't, but I think more often than not they do.
2. "2. Crash dummies only simulate full size adults, not teens, not children, not infants. Aren’t teenagers, children and infants passengers too? Why don’t they count in the ‘rating’ system?The crash dummies are wearing seat belts in all cases, front and rear seats...(everyone in vehicles always wears their seat belts, don’t they?)"
It's called a budget! I would love for them to test every body type but let's get real here. There aren't unlimited funds. Is it asking to much to extrapolate results from an adult to a teen? Infants are in car seats and how many of those are on the market? And yes everyone who cares enough about safety to read this article wears their seat belts.
3. "The crash dummies are wired to measure injuries to head, neck, chest, pelvis, legs and feet, but all these findings are not included in the rating. The ratings only measure head and chest injuries for frontal crashes and head injuries only for side crashes (evidently, other injuries are not serious enough to count in a government study). "
Okay the author is jut a complete idiot. The NHTSA side ratings DO NOT include head injury results, only chest. Granted that makes no sense whatsoever, but this guy has got to get his facts straight. If you want to talk about bogus ratings check out the Infinity FX IIHS rating. It gets good for frontal offset, but did you know the dummy hit it's head on the steering wheel THROUGH the airbag? Granted the impact was low, but that doesn;t qualify as safe in my book. Or look at the Galant IIHS side rating which is Good (their highest rating) yet it offers MARGINAL head protection for a rear passenger. In other words your kid could get their skull knocked but it still gets a Good rating. Bogus. If you ar interested in real safety ratings that try to properly weight as many factors as possible look at informedforlife.org.
4. "Impact assumptions are for similar vehicles, differing no more than 250 lbs. This means if you are driving a small, full size or luxury car and you hit an SUV or a minivan...the rating doesn’t count (and it certainly doesn’t count if you happen to hit a tractor trailer...those crashes might change the star ratings). "
And it says that at the web site. People need to get educated. Government can't teach us everything. And what does he suggest, crash the cars into every possible size vehicle?
5. "5. Finally, the rating is only referring to injuries that require immediate hospitalization or are life-threatening. "
Do we need to know the chance of getting a bruise on our elbow?
6. "How about rear-end crashes, what are the ratings for that? Well, here’s what the government says about that"
Get a clue and go the iihs web site where they do rear crash tests.
This article was just poorly done hit job on the NHTSA. There are issues to be dealt with but this guy is largely focused on the wrong ones. Go to informedforlife.org to get a better idea of safety.
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dgan 1:27PM (7/12/2007)
The point of the article was to give the reader enough information about the rating system so they could understand statistics better and maybe even think for themselves for a moment. Advertisers and "spin doctors" twist things to make them sound so believable that we are lulled into a sense of false complacency.
3, 4, or 5 stars are not going to save us from ourselves. We need to realize that traffic accidents and related injuries continue to increase regardless of the number of features the manufacturer installs.
NeoteriX 5:22PM (7/12/2007)
Exactly. The crux of the entire article's argument was "Testing should be done with unlimited resources and test every possible circumstance. Because in reality, testing is not like that, we should really look at test results skeptically."
That's like saying... Because you haven't seen that the Earth is round first hand... well, you should disregard all other indications of it.
Richard Warren 5:17AM (7/12/2007)
It's a joke, it's always been a joke, it will continue to be a joke and it's cost consumers thousands over the years.
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seoultrain 5:46AM (7/12/2007)
well, this "joke" is pretty much the reason why things like passenger airbags have become required, and side/curtain airbags are everywhere. Same goes for side-impact beams, crumple zones, active head restraints, etc. the list goes on. No matter what you think of crash test results, you cannot deny that such testing has forced manufacturers to build safer cars.
Rene Curry 5:09AM (7/12/2007)
I would like to see the Mercury Marquis test become the standard! Crash the test car into a 90s Mercury Marquis and see what happens!
:-)
It would be an eye opener. I could just see a great "myth buster" test in the works now.
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