Is sleeping in a car with the windows rolled up dangerous?

Discussion in 'Conspiracies' started by Neurostudent, Dec 16, 2021.

  1. Neurostudent Registered Member

    There's this weird conspiracy theory that is making the rounds. The conspiracy goes like this: car manufacturers don't want homeless people sleeping in cars, so when a car is off, the air vents automatically close. They say you must crack open a window, but this wouldn't be good in the winter time when it's cold, and you can't leave a car running while parked because of the risk of carbon monoxide poisoning. So, a homeless person in the winter time who only has a car would have no choice but to sleep with the car off and the windows rolled up.

    When pressed for evidence, this is the article they like to respond with; which is presented as something which actually happened.

    I was unable to verify if this is a true story. There are no photographs of the alleged 'couple' and the 'couple' mentioned they were opening up a group to warn the public about the ''risks'' of these new cars. I was unable to find said group, and it's been over seven years since the article was submitted. None of the key details in the story add up, and the car model is mentioned a suspicious amount of times in every iteration of this legend.

    Is a person at risk of suffocation from oxygen deprivation if they sleep in their car with the engine off and the windows rolled up? Let's put this conspiracy theory to rest!
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  3. DaveC426913 Valued Senior Member


    How much risk? Very hard to say.

    Unlikely to happen.

    Too many variables.
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  5. Neurostudent Registered Member

    Well, Mazda did respond to this story/urban legend saying that they were not aware of any design flaws with the Mazda 3. Mazda is a Japanese company, so safety (or unsafety features) features would tend to represent the country of origin - how does Japan feel about their homeless ''car camper'' population?
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  7. billvon Valued Senior Member

    Nope. Cars are "leaky" enough that you will get enough oxygen.

    Nor will you "suffocate from oxygen deprivation" in any normal circumstance in a closed area - as long as you can leave. CO2 buildup will alert you very quickly to problems with the air before oxygen levels get too low, even if you're asleep. (If you're trapped, of course, that's a different story.)

    Side note - some cars (like Teslas) have a "car camper" mode that will run the ventilation system off the traction battery. Since the traction battery is large, you could stay a week like that.
  8. sculptor Valued Senior Member

    Many years ago
    while going home from a new-years party
    I made it all the way across town (Lake Geneva) at 25 miles per hour
    As I approached the expressway--the speed limit increased to 45 mph
    and I thought: 45 miles per hour is too damned fast
    so. I pulled over under the overpass, cracked a window and went to sleep with the car running and the heater on
    Just before dawn, when the sky was beginning to get light, came a knocking on the window
    it was a cop, who asked me if I was OK
    I explained that after the party, I did not feel safe at speeds over 25mph
    He asked me if I wanted breakfast
    Yeh sure
    So he and his partner took me out to breakfast and bought me 2 eggs, toast and coffee
    I apologized for sleeping in the car---saying that when I got home, all I was gonna do was sleep anyway
    and he responded, No, that's ok, I'd much rather tap on your window than have to pick up the pieces of your body and stuff them into a body bag,
    As they drove me back to my car, they asked if i felt ok to drive now
    and I answered in the affirmative
    When at my car, they waved goodbye and drove off to attend to their duties.
    nice guys
  9. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

    Fat chance

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  10. exchemist Valued Senior Member

  11. sideshowbob Sorry, wrong number. Valued Senior Member

    I have slept three nights in a car - two people, no windows open and fully-reclining seats. Mind you, that was in the 70s, before the obsession with making everything airtight. I have also slept one night in a van in the 90s with three people and no windows open. I'm still alive - though I'll let you decide for yourselves about brain damage.
  12. Janus58 Valued Senior Member

    Consider this: Cars have a button that switches the air system to "recirculate", shutting outside air enter the vent system and just reusing the air already in the car. This is so that, for example, on a really hot day, the AC doesn't have to cool hot outside air, but air in the car that has already been cooled some. If the car was really "air tight" they would have to issue warnings telling people not to use it for extended periods of time.
    sideshowbob likes this.
  13. DaveC426913 Valued Senior Member

    Air tight when there's a small wind storm is somewhat different from airtight when there's no air movement.
  14. Tiassa Let us not launch the boat ... Valued Senior Member

    Two notes go here:

    1) It is true that often, the first I hear of a conspiracy theory is from someone pretending to debunk it.

    2) The Ars Technica article provided does not support the conspiracy theory.​

    It is easy enough to put this conspiracy theory to rest by simply reading the article:

    The Times explains that the couple's inability to unlock the doors stemmed from "a combination of stress, night-time, and what they called a lack of information from a car salesperson."

    Although the pair tried to summon aid by sounding the car's horn and tried to break the car's windows with the spare tire jack, they ended up stuck in the Mazda from about 7:00 in the evening of November 5 through about 7:45am the next morning. Neighbors found the couple in dire straits, with Mollieanne Smith unconscious and her husband Brian having difficulty breathing. Mrs. Smith required a three-day hospital stay to recover.

    All of the Mazda3 hatchback models sold in New Zealand, even the base model, are equipped with push-button starting and keyless entry via a radio-equipped key fob. In spite of the fob and the lack of keys to put into an ignition, the door lock mechanism on the Mazda3 isn't any more or less complicated than on countless other modern vehicles. The car has power door locks that can be operated by switches on the doors' arm rests; there's also a mechanical lock/unlock switch integrated into the door handle itself.

    However, the door doesn't automatically unlock when the interior handle is pulled—and therein lay the problem for the Smiths. According to the Times, the couple had been led to believe by their Mazda dealership that the key fob was the only way to unlock the doors; this mistaken impression, coupled with the fact that the vehicle was parked in their garage and that it was apparently too dark to clearly see the interior switches, led to the nearly fatal overnight stay.

    "Once I found out how simple it was to unlock it I kicked myself that I did not find the way out," Smith is quoted as having said. The Times also says that since going to the media with their story, the couple has been contacted by "about five" other people who have had "similar keyless-car experiences."


    It remains unclear what people expect when putting so little effort into inventing conspiracy theories. That is, we get that only the most gullible fall for this stuff, but, given the unreliability of the description, "this weird conspiracy theory that is making the rounds", it might also occur to wonder what rounds the conspiracy theory is making. And in a way, we have our answer: The conspiracy theory is apparently making the rounds among ... well, right, just how do we describe this market niche?

    This paragraph, for instance; it is so insubstantial, it could have been written by a bot.

    "unable to verify if this is a true story" — Take it up with the Otago Daily Times.

    "no photographs of the alleged 'couple'" — Well, to become internationally infamous for being not-quite mortally stupid on Guy Fawkes Day is the sort of accomplishment most people wouldn't tout on a regular basis.

    "the 'couple' mentioned they were opening up a group … I was unable to find said group" — Again, international infamy for being extraordinarily stupid on, even compared to the sort of stupidity that can happen on days of revelry.

    "None of the key details in the story add up" — That assertion is meaningless in its moment and context.

    "the car model is mentioned a suspicious amount of times in every iteration of this legend" — The car model is a known value; the alleged conspiracy theory extrapolates to other models and manufacturers.​

    Additionally, some basic intuition that goes here: Most homeless people living out of a car are not living in a car with all of its seals intact. The cold is the greater danger. We could probably build a laboratory environment for measuring the risks of sleeping in a given model of car, but it is also worth bearing two points in mind: First, the reason we don't hear about more people dying like this ought to be pretty obvious; second, the idea that auto manufacturers would deliberately build that kind of risk into their cars defies particular ranges of logic, perhaps the most persuasive being that of their insureres.

    Put this conspiracy theory to rest? Why would anyone breathe such life into it in the first place? There is nothing substantial about the description of the conspiracy theory; that is, even the conspiracism itself is weirdly insubstantial.


    Hutchinson, Lee. "New Zealand couple manages to lock themselves in keyless car for 13 hours". Ars Technica. 18 December 2014. 24 December 2021.
  15. RainbowSingularity Valued Senior Member

    im going to ignore all the other stuff because i cant be bothered
    & just stick with the basic science
    car manufacturers wont want customers being killed in their new cars
    its bad for business

    reality rarely meets an even keel when it comes to ignorant people & their whims.
    modern cars will be quite well sealed
    they will have venting to allow some air flow
    3 large males in a small new car turned off with vents closed
    likely they will die from Co2 poisoning
    its just a matter of how long

    1 small child locked in a new car for 24 hours would have enough breathable oxygen as long as the vehicle is not in direct sunlight or a hot climate

    now turn to average americans
    bad food bad diet

    place 2 big fat rude ignorant Americans in a new small car
    they would fart burp & talk soo much crap they would kill themselves with thier own toxic fumes

    2 fit healthy good diet
    could survive in the car for many days without food & water(not advisable)

    some people are aller4gic to fabrics & plastics & rubber
    so they may slowly become more poisoned by the fumes of the material of the car & eventually die after maybe 1 or 2 days with food & water
    assuming they dont poop in their pants & eat poop & die from ecoli poisoning as their liver shuts down & they die in terrible agony screaming in pain

    too real ?
  16. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

    Even if did poop and eat causing more ecoli poop think would take long time to die. Extra time to be found perhaps

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  17. exchemist Valued Senior Member

    Is this a crossword clue?

    Or are you just pissed?

    Or stoned?

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  18. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

    Only ever been pissed

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    Just rearranged icons on phone

    Added to Home Screen 5 persons I most chat with in WhatsApp and then grouped together

    What a exciting life

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  19. Neurostudent Registered Member

    A couple are claiming they almost suffocated in their new car after being in it through the night, because of something about cars ''being more tightly sealed these days with their airtight designs''. They had to stay in hospital for a few days afterward. The car was not running, so carbon monoxide was not a factor in this, and the car was parked in a garage, and it was night time, so heat was not a factor either. The door locks malfunctioned causing them to stay in the car overnight. They made a group warning people not to sleep in modern cars because there is a danger of suffocation. By the time they were found, the wife was unconscious, and the husband was having difficulty breathing. Medics said if they spent just another thirty minutes in the car, they would've both died from oxygen deprivation.

    Their dashboard vents were still in the open position set to outside fresh air. Would tighter door seals significantly affect the passive ventilation in a car? Or does most of the air freely coming into the car get through the HVAC vents so tighter seals wouldn't really affect the amount of passive air exchange? (The ducts are always open if the vents are set to open, even if the fan isn't blowing.)

    In 1998, Harvard did a study on the air exchange rates for stationary cars with no mechanical ventilation and windows rolled up. It varied between 1-3 air exchanges per hour, which is more than enough to prevent suffocation and more than 9 people would have to be inside of the car to be using up air faster than what is coming inside. The couple are claiming that because modern cars are ''better sealed up these days'' (referring to the door seals), they are now a suffocation risk.
    Last edited: Feb 12, 2022
  20. sculptor Valued Senior Member

  21. Neurostudent Registered Member

    2014 Mazda Hatchback sedan

    The studies I tried to find all seem to involve the Air Exchange Rates for vehicles with the intake set to 'Recirculate', which closes off the vents. For newer cars which don't have notched vent baffles, the Air Exchange Rate can be as low as 0.1 Air Changes Per hour. I can't find any studies on Air Exchange Rates for parked vehicles with the vents set to fresh air.

    Or do the vents automatically close when the vehicle is parked/off? In this case the vehicle wasn't running.
  22. Jeeves Valued Senior Member

  23. billvon Valued Senior Member

    That's how I know it's fake.

    You don't have difficulty breating because of low oxygen. You have difficulty breathing because of high CO2. In every case, if someone is in an enclosed area, the CO2 in the air will build up until it's intolerable and they feel panicked and like they must escape.

    This is because of the relative levels of O2 vs CO2 that are required to cause problems. The percentage of O2 in the air is 21%. If it drops to 10% (which you see at 17,000 feet - the top of a mountain) you will feel short of breath - but if you are sitting still you won't feel much in the way of ill effects. I've done this and it's valid.

    However, only 5% concentration of CO2 will make you VERY uncomfortable, and 7% will make you pass out if you experience for long enough.

    Thus it's the CO2 that will get you, every time. The only exceptions to this are in very unusual cases, like you're cleaning out a fuel tank of a rocket and the tank is full of nitrogen (an inerting gas used to pressurize fuel tanks.) In that case there is 0% oxygen, and you never notice because the CO2 concentration is also low. At least until you pass out.

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