IIHS vs. NHTSA car safety ratings

The ratings for IIHS and NHTSA don't seem to mesh with one another.

Does someone know any testing or rating specifics that could account for the discreptancies?

For example,

  • NHTSA rating for the 2007 Corolla w/o side airbags: front rating / side rating = 5 stars / 4 stars
    formatting link
    * IIHS rating for the 2007 Corolla w/o side airbags : frontrating / side rating = good / poor.http://www.iihs.org/ratings/ratingsbyseries.aspx?id=305 There is clearly some discreptancy. Does anyone have some insight into what it is?

We are interested in a new Corolla, with safety and maneuverability in mind.

Thanks!!

Reply to
runxctry
Loading thread data ...

The NHTSA is a government agency and crashes the vehicles squarely into a fixed barrier at 35 MPH.

The IIHS is funded by insurance companies and crashes the vehicles offset into a deformable barrier at 40 MPH, a much more severe test.

Reply to
Ray O

The IIHS doses not use the standard criteria, to which all manufacturer are required to build to be allowed to sell their vehicles in the US. In the first place, the IIHS tests at speeds exponentially above the NHTSA standard test. In addition the IIHS tests in collisions other than full frontal, for which the federal test are designed.

The vast majority of the most dangerous crashes are full frontal. The most important difference is manufactures MUST perform a minimum of FIVE REPEATABLE tests for EACH version of a particular model, to meet the NHTSA standards. I E the four door, the two door, with four and six cylinder engines and with standard or automatic trannys versions of each etc..

For any test to be valid scientifically, it must be repeatable and to the same standard criteria. IIHS test are done basically to present to regulators to set insurance rates. IIHS test are NOT repeated, completed only on ONE vehicle and therefore scientifically not sustainable or valid, regardless if the results are the good or bad. IIHS test have no relevance to the NHTSA standard test. NHTSA standard test is the test one should trust

mike

Reply to
Mike Hunter

If IIHS used a fixed barrier, what speed would give similar results to their 40 MPH test?

Reply to
larry moe 'n curly

The IIHS works for the insurance industry. They don't mind making you spend more if it allows insurance companies to spend less (or charge more). The IIHS is notorious for trying to force marginally effective "safety" device on the public in the hopes it will save their clients (the insurance industry) money. When your next car cost thousands more because it has almost worthless electronically stability control, write a thank you note to the IIHS. There is zero evidence that ESC is an effective safety device, but thanks to the tireless efforts of IIHS, every car sold in the US will soon have it. They did not make the same mistake they made when they tried to force ABS on the public. With ABS, they didn't push for it to be mandatory hard enough. There was enough data gathered to make it clear ABS was not an effective safety device, so the IIHS was unsuccessful in their campaign to have NHTSA make it mandatory. With ESC, they did not wait for any evidence to accumulate - they pushed hard a loud and convinced NHTSA not to wait for any actual facts. So all new cars will soon have ESC, which also fulfils the IIHS's dream of sticking us with ABS, since ABS is required to make ESC work. You've been screwed....

On the other hand, I do trust the statistics gathered by the IIHS (actually the HLDI). If you are concerned about safety, take a look at the Injury Loss Ratings (see

formatting link
). For small cars, the four door Corolla is in the middle of the pack. The average injury loss rating for all vehicles is 100. The four Corolla has a 159 rating (lower is better). The VW Golf and Jetta are two of the better cars in this class. The question is - is safety more important than cost and reliability?

Ed White

Reply to
C. E. White

Mike Hunter's explanation is a good one that describes the differences in the tests. The 2 tests are so dissimilar that just adding a fixed barrier would not give similar results. In the IIHS' offset test, only half of the front of the vehicle has to absorb the exponentially higher energy of the crash, while in the NHTSA test, the entire front of the vehicle is available to absorb the energy.

Reply to
Ray O

Interesting. I'm no fan of the insurance industry and it wouldn't surprise me. I'm curious as to your background on this subject?

I've never looked at data, but ABS always seemed like a good idea to me. My understanding is that it stops the vehicle in the shortest possible distance by keeping the tires right at the threshold of lockup/skidding. It sure seemed to work well with seat of the pants experimenting I've done with high-speed stopping with ABS on different vehicles.

Reply to
Doc

"C. E. White" wrote in news: snipped-for-privacy@corp.supernews.com:

More precisely, you should write a thank you note to all those lawmakers who made tort and insurance regulation the unholy mess it is now.

Were it not for regulations, liability exposure and "no fault", the insurance companies would not give a rat's ass how the car behaved in a crash, just like in the "old days" prior to the '70s.

Reply to
Tegger

Doc wrote in news: snipped-for-privacy@19g2000hsx.googlegroups.com:

He's right. Auto insurance tends to be a poor money-maker for many insurance companies on account of crushing regulation.

Reply to
Tegger

What I meant was, an IIHS test at 40 MPH into a crunchable barrier is equivalent to doing the same test at what speed into a rigid barrier? Sales people love to claim that the IIHS test is more severe because it's run at 40 MPH, but I don't see how, even if only the driver side dummy is considered.

I've read that car makers can choose how the government conducts some of its mandatory crash by either crashing the vehicle into a solid barrier, or jerking the vehicle to simulate similar forces. Why is the second choice allowed, and is it ever more realistic or severe than the fixed barrier test?

Reply to
larry moe 'n curly

"Doc" wrote in message news: snipped-for-privacy@19g2000hsx.googlegroups.com...

Personal experience, opinion, review of data on the subject, etc.

It is very hard to find good comparisons between ABS and non-ABS equipped cars. Often when magazines run tests, they make a comparison by using the same car with the ABS enabled and disabled (by pulling a fuse). This is a bogus method. Most cars with ABS have braking systems designed to take advantage of the ABS equipment. Since they have ABS they can install larger rear brakes and they don't include proportioning valves in the system. Instead, they depend on the ABS to prevent locking of the rear brakes first (locking the rear brakes before the front brakes usually results in a spin). With the ABS disabled you lose the proportioning function and the rear brakes lock first. If the car never had ABS, the braking system would have been designed to prevent this. Testing a car with the ABS disabled is testing a car with a crippled braking system and is not the same as comparing an ABS equipped car to a car that never had ABS. It is very hard to find cars with otherwise equivalent equipment for an ABS to non-ABS comparison. Usually cars without ABS are lower priced models with smaller/cheaper tires. My review of existing road tests and literature leads me to believe that cars with ABS probably can stop very slightly shorter on dry pavement that a car with the brakes locked given identical tires. However, the variation between tires is much greater than this difference. So if you are worried about stopping 5 feet shorter, you would be better off spending the cost of the ABS on better tires, and replace the tires more frequently.

On some low traction surfaces, the stopping distance advantage may be slightly greater - 10 feet or less. Again, better tires would be a better investment. There are some low traction surfaces where ABS sometimes greatly increases the stopping distance (gravel, snow). And in some cases ABS is totally worthless (glare ice).

The ABS fans always tout the claim that ABS will allow you to steer under extreme braking conditions. This is often true. However this is a mixed blessing for many drivers. In theory the ability to steer while braking hard, can allow you to steer around a potential collision. This can actually make things worse if instead of plowing straight ahead into the rear of another vehicle, the vehicle is steered into oncoming traffic, or off the road where the vehicle rolls over. For many drivers, plowing straight ahead is the safest option. It may result in more property damage, but this is a small price to pay compared to the billion spent on installing ABS in all vehicles.

For a few brief years, when ABS was first available, it was possible to make reasonably good comparisons between GM cars from different years. The statistics gathered showed that ABS equipped cars had a higher driver death rate than cars without ABS. Both the IIHS and NHTSA tried to explain this away. They never did. More recent statistics are murky because of the factors I previously mentioned (cars with and without ABS are not directly comparable).

At one point NHTSA proposed that ABS be mandatory. After reviewing the statistics they dropped the proposed rule. Even the IIHS admits there is no compelling evidence that ABS provides a net safety benefit.

I have no problem with ABS (or ESC) being offered as an option. I strongly object to having it rammed down my throat. My chief objection is cost. I do not believe ABS is a cost effective safety device. The billions spent on ABS could be better spent on other safety measures (like better tires, replaced more often). ESC is more of the same. You may be able to make the argument that it is cost effective for top heavy SUVs, I doubt it is useful for passenger cars. The benefits versus cost should have been studied more extensively before it was made mandatory.

My comments only apply to 4 or 3 channel ABS on passenger cars. I do think rear wheel ABS is a good thing for load carrying vehicles (trucks and SUVs). The front/rear brake load for passenger cars is relatively constant and it is possible to do a decent job of designing in the proper front/rear brake bias. For trucks and SUVs, the load on the rear brakes is greatly variable. For load carrying vehicles it is difficult to size the rear brakes to handle the maximum load and prevent them from locking up when unloaded. Rear wheel ABS is perfect for handling this situation.

Ask yourself this - Who benefits from mandatory installation of ESC (or ABS)? Insurance companies may (possibly through a reduction in the number of minor collisions). The manufacturers of the equipment definitely benefit (they spend big bucks promoting the supposed advantages). Car manufacturers also benefit. If ESC (or ABS) is mandatory, no one is at a competitive disadvantage, and everyone can make additional money because of the increased cost of the vehicles. Who is looking out for your best interests? Ideally NHTSA should be looking out for the best interest of the public. However, do you think NHTSA is going to make a strong stand against any device heavily promoted by the insurance and auto industries, particularly when they are being promoted as "safety" devices.

One last thought - when was the last time you actually needed ABS? In the last 15 years I've owned a number of vehicles with ABS. I've never had the ABS active during an actual driving situation. I have deliberately provoked the activation of ABS. In particular my current pick-up has very sensitive ABS and it can be provoked into action on dirt with minimal effort (and disastrous results - the stopping distance goes up greatly - an actual safety problem for me). It is my opinion that the people that can most benefit from ABS are the same people who least need it (good experienced drivers). Less competent drivers are the drivers that are likely to be alarmed by the activation of ABS, or steer into a worse situation because of the "benefits" of ABS.

Regards,

Ed White

Ed

Reply to
C. E. White

All scientific tests by their nature, must be set to a standard, if they are to be meaningful. Several years ago the IIHS conducted tests that backed the vehicle into a six inch pole. Those vehicle that had a larger rear areas like wagon and SUV sustained more damage than sedans with a smaller area that would be damaged, even though the majority of passengers in wagons and SUV are less likely to be injured in a rear collision than those in a sedan.

Everybody cried foul and the test was eliminated by the IIHS. Small SUVs like the RAV4 and CRV with the tire outside, were particularly unfairly disadvantaged.

If we had to design a vehicle to protect passengers in every type of accident in which the vehicle might be involved, few could afford to buy it.

Years ago GM engineers did design such a vehicle. At the time when a full size car was selling for $7,000, it would have cost nearly $80,00 IF sold in volumes of 500,000 or more. Even at that the fuel mileage was in the single digits

The fact is slightly less than 8%, of the sixteen or so millions of new vehicle sold in the US every year, will be involved in an accident suffice to deploy the SYS in their LIFETIME. A more telling statistic is only 2% of those 8% will be involved in a rollover. Only a fraction of those will be one in which the rollover was NOT the result of being struck or run up or down and incline. Yet today buyers, because of the anti SUV crowd and the we know it all safety nuts, must pay several hundreds more to buy vehicles with stability control, albeit it optional or standard, that will NOT do anything to prevent a rollover that is the result of being struck or run up or down and incline.

mike

Reply to
Mike Hunter

They replaced the pole with a curved bar. See

formatting link
. IIHS is still pushing for ugly heavy bumpers. No thank you. I haven't damaged a bumper since 1981. If the IIHS gets it's way, I'll be forced to spend hundreds more for ugly useless bumpers that will cost me still more in reduce fuel economy, and if I am in a collision at over 4 or 5 mph will be much more expensive to replace. I am willing to pay a little extra in insurance premiums to avoid having ugly mostly useless bumper shoved down my throat. If we allow the insurance industry to design our cars, we will soon have expensive crap. Ed

Reply to
C. E. White

My understanding is the theory is that Joe & Jane average aren't likely to be trained and adept at threshold braking and that with ABS they don't need to be. Typical reaction in panic stop situation is - to panic - slam on the brake pedal and lock 'em up.

I suspect those 10 feet - if that's really the difference - in many instances could mean the difference between contact and no contact - injury/death or no injury/death. However, without doing any tests, I'd make a cashless wager that from higher speeds, the distance is going to be more than 10 feet.

Maybe I have a misunderstanding as to how ABS works. I thought it sensed wheel rotation and prevented it from reaching 0 until you reach a certain point of inertia. Why would it increase stopping distance in the situations you mention?

In that situation it seems the defect is in another safety system called Userbrain=99 which is supposed to sense such conditions and prevent the vehicle from being on the road in the first place.

Userbrain=99 seems to often fail in other aspects of vehicle operation such as leaving adequate following distance, treating the highway as if it were a LeMans race and all other drivers merely slower competitors to be weaved around, going too fast for prevailing conditions, modifying the suspension & tires, adding airfoils etc. without the vaguest idea as to how it'll effect the characteristics of the car, etc.

The commercial version of Userbrain=99 that can be found on big rigs and various transport vehicles often has a whole additional set of defects such as causing the vehicle to behave as if driven by a fatigued, pea- brained redneck asshole with anger management issues. Or causing the hold-downs on the covering to fail and the contents of the truck to spill continuously onto the roadway as if the driver couldn't give a rat's ass what damage they're leaving in their wake.

A repair method I highly favor is to forcefully and repeatedly strike the Userbrain=99 housing until it functions correctly.

Hmm. If in fact this is true, it would seem this isn't a small point. Any theories? Maybe a false sense of security that inspired complacency?

Reply to
Doc

The increased severity of the IIHS test is not because it is run into a deformable barrier, but because only half of the front of the car hits the barrier, (think hitting a puncing bag with only 2 fingers instead of with your fist) and the 5 MPH higher speed means that the energy that has to be absorbed is close to double the energy at a 30 MPH test. In other words, there are 3 differences - the vehicle strikes the barrier differently, the barrier is of a different construction, and the speed is higher. Also, as Mike Hunter pointed out, the test is not repeated (and so not confirmed). If the IIHS test was run into a rigid barrier, the difference would be even greater.

I'm pretty sure that automakers cannot chose how the government conducts crash tests. If there was a choice, the test results would be meaningless. Automakers do conduct in-house tests during a vehicle's design phase. Computers are now used to predict crash results before cars are actually made so that they don't have to crash a prototype only to find out that the design wasn't good enough.

Reply to
Ray O

My understanding is the theory is that Joe & Jane average aren't likely to be trained and adept at threshold braking and that with ABS they don't need to be. Typical reaction in panic stop situation is - to panic - slam on the brake pedal and lock 'em up.

Tat is the theory and works in practice. However several things can happen that counter the "goodness." 1) The pulsing brake pedal upset people not familar with the action of ABS and they react negatively (take there foot off th ebrake, etc.). 2) Old people remember there driver's ed lesson and jump the brakes any way - negating the advantage of ABS. 3) In a panic situation, if you lock your brakes, you plow straight ahead. With ABS you can actually steer - in theory a good thing, in practice the results are mixed becasue inexperienced drivers can steer into a worse situation. Manufacturers have tried to overcome 1 by adding brake assist features. These features actually inclrease brake pressure in situations that the ABS computer interperts as panic stops (i.e., the system presses the pedal harder for you). They try to overcome 2 by education - read your manual. There is no way to overcome 3 - people in panic situation do stupid things. Additional driver training, and practing braking in a wet or icy parking lot could help.

I suspect those 10 feet - if that's really the difference - in many instances could mean the difference between contact and no contact - injury/death or no injury/death. However, without doing any tests, I'd make a cashless wager that from higher speeds, the distance is going to be more than 10 feet.

Of course it would depend on the car, the tires and the road surface. However, at normal highway speeds, I doubt the difference would be greater than 10 feet unless there was standing water. In this case, nothing is going to help. It is my not my contnetion that ABS won't reduce stopping distances on wet pavement. It is my contnetion that most people could acheieve the same or better results by buying better tires, keeping them properly inflated, and replacing them more often. This would be less expensive than equipping the car with ABS. Of course doing this and having ABS would potentially reduce stopping even more. However, I see many cars that have ABS and worn out cheap tires. Those drivers would be far better off without ABS but with good tires.

You might want to review the information at

formatting link
. Keep in mind that I am fully in support of requiring rear wheel ABS on trucks and SUVs. There is a clear safety benefit for this requirement. For tradional passenger cars, the benefit is hard to find. If you factor out trucks and SUVs with ABS from the statistics, there is no benefit to be found for passenger cars.

Maybe I have a misunderstanding as to how ABS works. I thought it sensed wheel rotation and prevented it from reaching 0 until you reach a certain point of inertia. Why would it increase stopping distance in the situations you mention?

On loose surfaces (snow, gravel, dirt) a locked wheel will build up a berm in front of the tire (think dirt wave) when sliding. This reduces the stopping distance. ABS prevent the wheels from locking, so no berm, and since the surface is low traction, the stopping distances go up.

In that situation it seems the defect is in another safety system called UserbrainT which is supposed to sense such conditions and prevent the vehicle from being on the road in the first place.

UserbrainT seems to often fail in other aspects of vehicle operation such as leaving adequate following distance, treating the highway as if it were a LeMans race and all other drivers merely slower competitors to be weaved around, going too fast for prevailing conditions, modifying the suspension & tires, adding airfoils etc. without the vaguest idea as to how it'll effect the characteristics of the car, etc.

The commercial version of UserbrainT that can be found on big rigs and various transport vehicles often has a whole additional set of defects such as causing the vehicle to behave as if driven by a fatigued, pea- brained redneck asshole with anger management issues. Or causing the hold-downs on the covering to fail and the contents of the truck to spill continuously onto the roadway as if the driver couldn't give a rat's ass what damage they're leaving in their wake.

A repair method I highly favor is to forcefully and repeatedly strike the UserbrainT housing until it functions correctly.

Userbrain T can compeltely replace ABS at a greatly reduce cost.

Hmm. If in fact this is true, it would seem this isn't a small point. Any theories? Maybe a false sense of security that inspired complacency?

Inappropriate reaction to the pulsing brake pedal, steering into trouble, etc. See above.

Ed

Reply to
C. E. White

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.