Less safe than what the test should have been with one simple change.
The IIHS 40% 40 MPH moderate overlap crash test in to a fixed barrier uses a deformable barrier in front of the fixed barrier. This barrier absorbs some energy, so the test is actually less severe than 40MPH in to a fixed barrier. I don’t know how much less. But I do know that the amount of energy absorbed by that deformable barrier is more in relation to the test vehicle for small vehicles than large ones, giving small vehicles an advantage. This means that heavy vehicles such as trucks and SUVs actually have to be built stronger in front in proportion to the vehicle weight, or be longer in front to lengthen the crash pulse, compared to smaller vehicles to achieve the same result. Light weight vehicles can rely on the barrier absorbing more energy. So the result is the opposite of what the desired result should be. The size mismatch of vehicles on the road is bad enough without compounding the problem by having the heavier vehicles proportionally stronger for frontal crashes.
How it should have been is heavy vehicles should be weaker in front since they will more likely crash in to lighter vehicle, and small vehicles need to be stronger or longer in front since they will likely hit a heavier vehicle. This could have easily been done by using a heavy movable barrier, such as a 10,000 pound block on wheels with no deformable barrier in front. Heavier vehicles would cause the movable barrier to roll back faster, allowing them to get by with a front end that’s a bit weaker.
It’s entirely reasonable for lighter vehicles to get lower crash test scores, and pressure from the industry should be ignored. This is an honest rear world representation.
Also, this is not the only problem with the IIHS 40% overlap test.
I’m adding this video in response to that stupid 1959 Bel Air crash test people pushing their agenda use to disrupt discussions and to prove that all modern cars are safer than older ones.
I can see you’ve been Googling again… Why can’t you let one posting (What new cars have older features and reliability without the newer complexities and styles?) run it’s course with starting another…
You are like a firebug who starts fires everywhere you go… When I was back in school (1960s) there was this little guy (about 5’4”) who kept starting fights… (Did you hear what that guy said about your mother, your girlfriend, etc…). Then he would stand back and watch what he started play out…
That worked right up to the time he tried it on two guys (Did you hear what he said about your mother?) but he did not know that although the two guys had different last names, they were from a blended family and both had the same mother (different fathers…).
Vehicle is tested against static barrier.
Not against another car.
The offset barrier test concentrates forces on area outboard of frame rail.
It forces wheel into driver footwell area.
IF footwell does not deform beyond test limits, it passes.
He longs for The Good Old Days, when cars collapsed upon impact, like this '59 Chevy did. The difference in passenger protection between the old Chevy and the 2009 Chevy was incredible, and the difference would be even more pronounced with cars made in the last decade.
No mention of exact speed other than being excessive for that highway Rear ended a bobtail semi. Driver tried to run from the scene but ended up being captured. Front crumble zine on that Vw did its job. Dui according to reports.
That may have been the intention of the deformable barrier, and it likely helped prevent designers from doing the easiest thing which is making the frame rail strong and leaving the area behind the wheel as flimsy sheet metal. But as I described, it has the perhaps unintended effect of giving an advantage to lighter weight vehicles in the crash test. A combination of a deformable barrier and a free to move barrier might have been the best setup.
Front crumple zone did nothing. The length of the vehicle bumper to front bumper mounts is close to the same. The upper fender supports and strut towers helped save the day, a feature of unibody vehicles. The high up structure is quite flimsy on many body on frame vehicles, which usually wouldn’t even have strut towers. Credit goes to the safety of the unibody. That crash might have only been 30 MPH.
Nobody else responded to the topic of the discussion. That video of the 1959 Chevy needs to be banned. Cars didn’t even have seat belts then.
It’s only an issue to people who dislike questioning the status quo. People saying cars are safer than ever and nobody is allow to question that is who the fight is against.
On a more positive note, the IIHS small overlap doesn’t have the deformable barrier issue that I mentioned, and a lot of vehicles struggled to do well on it, especially small ones that no longer have the deformable barrier advantage. Although there is still the issue of the IIHS prioritizing small injuries above life saving designs. A broken ankle will make a vehicle fail.
So now there are two discussions that you disagree with going on at the same time. Maybe you would like to turn the whole place in to your private blog and only post articles that you like, and only allow comments that you approve of?
You know, besides your continuous string of contentious questions, you remind me of my granddaughter who keeps asking, “But why Mommy?”
You ask a question, you get an answer, and you challenge the answer. You seem to relish strife… As with my little granddaughter, you are not looking for an answer; but in your case you just want to cause conflict, and then you switch it up with a, “But why Daddy?”
Is it too much to ask you to not participate in a discussion that possibly some others might want to discuss with factual statements and valid questions? At least more than one frequent contributor has decided to stop posting to the verbal abuse false accusations and other word games.
If the idea was to make every car equally safe in a crash, they would all be the same. To the extreme, you can’t make a bicycle safe in a crash with a truck. Small cars are inherently at a disadvantage. The testing is designed to reveal limitations in the design for specific conditions, not make every car equivalent in results.
The actual test results are not about the barrier or the damage to the vehicle. They are measuring the impact forces transferred to the occupant to gauge survivability. Making a truck front end weaker to allow for smaller vehicles compromises the truck for other types of crashes that are just as likely to occur.
The population motor-vehicle death rate reached its peak in 1937 with 30.8 deaths per 100,000 population. The current rate is 13.4 per 100,000, representing a 56% improvement.
In 1913, 33.38 people died for every 10,000 vehicles on the road. In 2023, the death rate was 1.57 per 10,000 vehicles, a 95% improvement.
In 1923, the first year miles driven was estimated, the motor-vehicle death rate was 18.65 deaths for every 100 million miles driven. Since 1923, the mileage death rate has decreased 93% and now stands at 1.38 deaths per 100 million miles driven.
The 2025 Jerp Gladiator improved its score in the test with seat belt pretensions, force limiters, and curtain side airbags. Test is mainly about rear passenger safety.
The small overlap IIHS test, and the NHTSA 35MPH test is equal for all vehicles regardless of weight. The tests are valid in a single vehicle crash in to a fixed object or in to another vehicle of the same design and weight. What you say about not making every car equivalent in results is true, and that’s the problem. The test gives lighter vehicles an advantage. In other words, the test is less severe for lighter vehicles. For example what if NHTSA tested compact cars at 32 MPH, and trucks or SUVs were crashed at 38 MPH? What would be the point of that? The inherent disadvantage for lighter vehicles is only when a heavier vehicle is involved in the accident.
If two compact cars and then two SUVs hit head on, all going the same speed, the people in the SUVs will be better protected even though both have Good ratings from the IIHS. This is because the severity of the IIHS test is higher for heavier vehicles.
In an extreme example, a very light vehicle could be built without a crumple zone at all, position the footwell directly behind the bumper, put the engine in the rear, and rely entirely on the deformable barrier in the IIHS test to absorb energy, and pass the test. The safety would be a total failure in the real world though.
Yes making the heavier vehicles weaker would compromise the safety of the heavier vehicle. But why does IIHS promote this? Is the value of the life of an SUV driver worth more than the driver of a compact car? Shouldn’t IIHS consider all drivers and passengers equally? Why crash test compact cars at a lower speed than SUVs? That is the equivalent of what the deformable barrier does. It should be the other way around since safety is more important to occupants in light weight vehicles so the test requirements should be higher not lower.
If we have reached the point where we both understand how the IIHS 40% crash test tests lighter vehicles at a lower speed than heavy vehicles, then I’m happy. By the time the barrier is fully compressed and the real test starts, lighter vehicles will have slowed down more. Whether or not it is a good thing to lower test severity for light weight vehicles is another matter, and we can discuss that too! Perhaps owners of compacts generally don’t prioritize safety so the tests aren’t as important.
