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HIC-15 crash test scores

Discussion in 'Gen 4 Prius Technical Discussion' started by laird, Dec 22, 2021.

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  1. laird

    laird Junior Member

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    I bought a 2018 Outback to replace my 2006 Prius and while there's lots to love, the cam carrier seal issue is a real drag and I'm looking to move back into a Prius or Sienna so I'm reviewing IIHS data and getting really puzzled.

    I expected the 2022 Prius to crash better than the 2006 and it does seem to return impressive results in small overlap and side. The B-pillar is not as strong as it should be and only gets a -17.0 (outback is mid 20s) but much better than the 2006.

    The big issue is that projected head injury from the HIC15 scores are not great at all:
    2006 prius - moderate overlap HIC-15 337, side HIC-15 274, b-pillar -6.5
    2022 prius - moderate overlap HIC-15 196, side HIC-15 434, b-pillar -17.0

    for comparison
    2021 sienna - moderate overlap HIC-15 153, side HIC-15 63, b-pillar -23
    2021 rav4 - moderate overlap HIC-15 321, side HIC-15 124, b-pillar -21.5
    2018 outback - moderate overlap HIC-15 117, side HIC-15 112, b-pillar -22

    https://en.wikipedia.org/wiki/Head_injury_criterion

    If I understand that correctly the 2016-2022 prius is substantially worse scoring for side impact head injury than my old 2006 prius. If true, that's just bonkers.

    2006 Toyota Prius
    2022 Toyota Prius
     
  2. laird

    laird Junior Member

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    Checked with local dealers and they didn't have much to add. Talking with the 800-toyota folks now but it's not looking good.
     
  3. alanclarkeau

    alanclarkeau Senior Member

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    The goalposts keep changing with the testing - at least here. A car which got 5 stars just 6 yrs ago might only score 3 or 4 with new testing. But the reality is - anything which got 5 stars back in 2015 (when Gen4 was designed and first tested) is admirably safe.

    And they're a prescribed accident - the way probability works is that they don't go to any set prescription.

    I recall a tiny SUZUKI 4WD clipped a NISSAN PATROL near home (long time ago when SUZUKIs were tiny) - and the Suzuki was barely damaged - the Patrol was a write-off after a full spectacular rollover. But if the hit was 200mm differently, or the speed differentials 5% different - could have seen a drastically different outcome.

    Don't worry - it's a VERY safe car.
     
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  4. laird

    laird Junior Member

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    I appreciate the input but the HIC-15 score is very objective and not subject to any amount of goalpost moving like the stars.

    I spoke to Toyota with the hope that the test they'd administrated and reported to IIHS was incorrectly communicated and a simple clerical error had been made. Perhaps that support request will bear fruit beyond the call today.

    The 434 score if accurate is a measurement of substantial TBI risk in side impact.
     
  5. laird

    laird Junior Member

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    One takeaway is that Toyota has done a fantastic job with the Rav4 and Sienna.
     
  6. bisco

    bisco cookie crumbler

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    i have to agree with alan. it's the same with epa mpg testing.

    i would investigate the iihs process over the years, if it was of concern to me
     
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  7. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    My advice would be to ride a motorcycle regularly for a year or two.
    Or?
    Maybe a deployment or two to the Middle East.

    After that, car crash "statistics" will see kind of trivial.

    I have too many submarine patrols under my belt to worry about things like traffic accidents..... :ROFLMAO:
     
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  8. Mambo Dave

    Mambo Dave Active Member

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    What you're seeing in crash testing may be why the RAV4 is miserable to get in and out of. The low roof / door-sill means that I had to tuck my head a lot more to get in and out of it than I do the Prius.

    I have to live and work with the vehicles I buy - bending my neck that amount (likewise for the Corolla, and numerous other cars from other makes) earns me pain over time, and an out-of-whack back over months. You may appreciate climbing into and out of a roll cage, but I sure as hell don't. That's why I settled on the Gen4 Prius out of it, other Toyotas, and a number of the competition's vehicles.
     
  9. BlastFromThePast

    BlastFromThePast Junior Member

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    Concerning the front end crash test, I believe it's a trade off between designing a vehicle that performs well with minimal minor injuries on the 40 MPH deformable barrier crash test versus making a vehicle that can save your life in a higher speed crash. Designing the restraint system to minimize minor injuries in the 40 MPH test can be done by having softer airbags and weaker seat belt load limiters. The weaker seat belt load limiter and fast deflating airbag can prevent the dummy from rebounding and hitting the B pillar, but at higher speeds the restraint system will bottom out leading to severe injury or death, especially if it's a heavier person. I wouldn't be so worried about the head rebounding and hitting the B pillar. The insurance industry funded IIHS may be concerned about it, but their goal is more reducing injuries than saving your life. I would almost rather wear a helmet when driving and keep the stronger airbag than have the restraint system optimized for a lower speed crash. Apparently an HIC rating of 337 for the 2006 Prius or 197 for the 2022 Prius is far from being severe or fatal injury.

    I made a lot of people mad posting this on another forum, but here is what happens when a vehicle that is optimized for the 40 MPH test is crashed at 50. Even at 50 the structure holds up well enough, but the restraint system bottomed out, resulting in severe neck and head injury due to hard contact with the steering wheel, and the crash is likely fatal with just 10 MPH of speed increase. At 55 MPH, the structure collapses so an optimized restraint system probably wouldn't matter anyway. The 50 MPH test received an IIHS rating of Poor. Here is the AAA funded 50 MPH and 55 MPH crash test:


    edit: The following two paragraphs are based on an incorrect interpretation of crash test data. For the IIHS side impact test, the numbers for the 2022 don't look good at all! The B pillar intrusion of 17cm in the 2022 versus 6.5cm for the 2006 seems odd. The only good reason I can think of is the door beams in the 2022 are stronger than in the 2006, causing the B pillar to be pushed in more, instead of the doors bending in. The IIHS uses a honeycomb structure as a bumper on their side impact crash sled. This tends to distribute forces evenly, but I think it is a poor representation of a real vehicle. Most real vehicles have strong frame rails, no bumper on the outside edges of the frame rails, and fairly weak collision strip in between the frame rails. The IIHS has recently updated the test with more real vehicle like crash sled, and car makers are having to make stronger doors because of it, but that's irrelevant here since this says it is the original test.

    So it must be that Toyota reduced the weight and strength of the side impact structure in order to maintain the same vehicle weight and still get a good rating on the small overlap test, which requires adding a not insignificant amount of weight and structure to the area behind the front wheels. This test was also done by Toyota and not IIHS, so that must be why they don't have pictures of it.


    edit: I was suspecting some kind of error after looking at the video, and I believe your interpretation of the B pillar intrusion number is incorrect, and I didn't realize it either. Negative numbers indicate how far the the intrusion stopped short of the driver's seat center line. The bigger the negative number, the less intrusion there is. This means the 2022 Prius has 10.5cm less side intrusion than the 2006.

    edit2: I suspect the greater head injury in the 2022 Prius is due to less low down side intrusion, which results in the torso not being pushed as much. This in turn results in the head not moving away from the window with the torso prior to contact with the side airbag. Consequently, when the head does hit the airbag, it hits harder and more on the side rather than more on the top as the neck is pulling the head away from the side airbag.
     
    #9 BlastFromThePast, Dec 29, 2021
    Last edited: Dec 29, 2021
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