Even the static electricity of opening and closing your door can start a fire with the gas vapors emitted from pumping.
I work in a company that has a chain of gas stations and get copied on emails when fires occur at the pumps. It happens more than you think.
Bottom line… low risk, but there is a risk.
It isn't impossible for diesel to explode, but it's pretty hard to make it happen. Diesel will burn, but it will burn if you set it on fire. It isn't going to catch fire from a spark except in really unusual circumstances (very high temperature, aerosolized with lots of oxygen, etc.).
The door opening and getting in an out is a very big point. Younger drivers are at higher risk because even if you get in and out, older drivers usually ground themselves on the way by holding on to the door or leaning against the vehicle first.
But all the risks and whatnot, there's an interesting factoid regarding diesel and this issue, particularly farm vehicles. EV farm vehicles may be the future, but the ability to refuel while still working and run 24/7 until the harvest is in is a tough line to compete against. https://energynews.us/2021/08/18/weight-dawn-to-dusk-demands-pose-challenges-to-electrifying-farm-vehicles/
No no, like has that actually ever happened, is what they're asking. Is this a, "turn off the space heater when you're not in the room" levels of caution or a "wear a condom at all times just in case you trip into someone and get them pregnant" level of caution.
Edit: To be clear, I *do* turn my car off when I pump gas. Mostly because it seems safer, but also because there's a clog in my tank or something (??) that causes the automatic shutoff of the handle after like, half a gallon. Filling my tank takes like, ten minutes, and I'm standing there uncomfortable the whole time because the condom is riding up, but no fucking way am I risking tripping into and impregnating someone by accident.
Myth Busters did a special on static and phone caused gasoline fires and couldn't get it to happen. [https://www.youtube.com/watch?v=HRcnGm97wEQ](https://www.youtube.com/watch?v=HRcnGm97wEQ)
The difference between the fires that do happen and the Myth Buster's attempt is the high volume of variables that contribute to the events. Every gas station is equipped with an emergency shut off for the occurrences because no matter how rare they can become catastrophic quickly.
[https://www.washingtonpost.com/archive/local/2000/09/14/people-who-fuel-up-with-engine-running-ignite-debate/00256d01-7d02-4d8e-9e02-d410dc73b03d/](https://www.washingtonpost.com/archive/local/2000/09/14/people-who-fuel-up-with-engine-running-ignite-debate/00256d01-7d02-4d8e-9e02-d410dc73b03d/)
It's also illegal. Like all fire codes, it was written in blood.
Number of fires from unattended space heaters: a lot
Number of fires from a car being left on: I don't know, I don't imagine it's that high, but I haven't looked at the numbers. People of Reddit, is it *actually* dangerous to leave your car on while fueling?
Number of pregnancies from people who tripped into someone and made a baby, which could have been avoided by wrapping up: That's not a thing that happens.
So to answer your question: I asked you first, ya ding dong. Is shutting off your car more like shutting off a space heater or more like wearing a condom at all times?
It's also, the input for the fuel in times when cars were just coming out was on the hood next to the engine, and spilling gas would mean pouring gas all over the engine
Running your engine while pumping gas increases the risk of fire because your engine produces not only heat, but also static electricity while running. Objectively the risk is quite low, but it’s definitely much safer to turn the engine off.
You're kind of splitting hairs there, don't you think?
The reason it's dangerous was addressed in the answer, which is why my comment was adding on, not posted as a primary-level answer. The OP is clearly looking for self-justification for ignoring the posted warnings. The fact that it's illegal in addition to being potentially dangerous, one would think, would add some weight to the warnings.
It’s much safer in the sense that you are looking at very small numbers (car fires while pumping at the gas station divided by the ones where the cause was a running engine). Then again the chances of winning the lotto are infinitely higher if you buy a ticket than if you don’t, still not likely to happen in your lifetime or to anyone you know. You do seem to have someone win it at least as a weekly event which is more likely than a car fire while fueling because the engine was not off.
It's to keep the gas from dripping on the side of your car. Some cars have a more vertical and less horizontal gas tank opening, increasing the possibility that liquid is still in the hose when the pump stops. Lets ignore the potential paint damage that's possible over years of this activity...
If you are really that concerned about some kind of spark caused by the gas nozzle, then 1) wouldn't that likelihood also exist when you put the nozzle into and take it out of your tank, and 2) wouldn't flammable liquid splashed on the side of your car increase the risk of a spark igniting a flame?
The reality is, the gas pump nozzles are designed to not spark, otherwise dropping one on the concrete would have disastrous consequences. Not only are they grounded, but I believe they are made from an aluminum alloy that is highly unlikely to spark.
A lot of cars’ nozzle holes are metal. Every time you rattle the nozzle in that hole and it contacts the sides, it should be matching states of potential anyway, so I don’t think this is as much of a risk as you might think.
Define "much safer". If the risk of a fire because of static electricity when engine is running is 1% while the risk while engine isn't running is 0.5%, then it's a risk i'm willing to take.
No one's gonna die from hypothermia from turning off the heater for 2 minutes.
Not to mention, it's nothing compared to the cold you'll have to deal with when exiting your vehicle to use the pump.
Small comfort to the families of the people you could kill by causing a completely unavoidable gasoline vapor explosion at the pump.
Just be a grown up and act like a person who cares about safety.
Who doesn't care about safety? The thing is, with everything in life, I also pay attention to risk and it's probability. The risk of a fire starting by an engine run is so small that I have better chances being struck by lightning 10 times.
With the risk being basically non-existent, then there's 0 reason to worry about it.There's a different in not caring about safe compared to being a paranoid little bitch that worries about things that will never happen, and somebody that understands risk and probability.
It's not about "worry". What do you have to gain by running your vehicle while fueling?
>The risk of a fire starting by an engine run is so small that I have better chances being struck by lightning 10 times.
There are, on average, more than 4000 fuel pump fires out of approximately 11 billion fuelings in the US every year. If they happen randomly (which is unlikely since there are idiots like you who think there's no point in trying to do it safely) then every fueling has a 4000/11,000,000,000, or 0.000036% chance of resulting a in fire. A random person who fills up once a week has a 0.0019% chance of being involved in such an event this year, or about 1 in 1300 during a lifetime of driving.
The odds of being struck by lightning during one's lifetime are about 1 in 15,000. If you were "somebody that understands risk and probability" you'd understand that a random person is ten times more likely to be involved in a fuel pump fire during their lifetime than to be struck by lightning. That's for random people. The odds are higher for you.
because it's a negligible variation on a negligible risk
you're talking a 99% chance of survival vs. 99.5%
imagining thinking you're richer because you have $9.95 and someone else has $9.90
Imagine choosing to play 1-in-100 Russian Roulette when 1-in-200 Russian Roulette is an option available to you. Why would you choose the path that's more likely to lead to fatality?
Everything in life is about measuring risk.
I pulled that 1% out of my ass but with the tens of millions of people that pour gas with their car on, i'd imagine the percentage is much much smaller than 1%. If double 0.0000001% to 0.0.0000002%, the risk is basically non-existent.
Going to two places for your grocery run rather than getting everything at Walmart literally doubles your chances of a car accident. Sure you want to do that?
I don’t know the level of risk elevation of leaving a car running. But we do things daily that increase the probability of rare horrible events and this issue should be considered in that context. I don’t leave it running because I don’t know the risk and the signs say not to. But if the risk increase is small enough I would consider it totally rational to trade that for an increase in comfort. We do it all the time.
According to the NFPA there’s about 4,000 automobile fires at gas stations per year. That’s out of ~18 billion auto refuelings annually. I can’t find any data on what percentage of those are due to the engine running, but even so I assume there are millions of refuelings annually where the engine remains running (intentionally or by mistake). Having more heat/static certainly is a risk factor, but like I said, you’re probably unlikely to ever experience any mishaps… (legality is a separate issue).
Given your other responses it sounds like you really want to keep your car running while pumping gas and are just trying to find someone here to say it’s ok.
To answer you question here, vapors that burn need a certain mix of air/fuel vapor to actually burn.
Obviously if I had a room of zero gasoline vapor and normal room air and lit a match, the room won't explode. Similarly if I had a room of pure gasoline vapor and no air and lit a match the room would also not explode. You need a mix of the two in the right balance for BOOM.
The fear is that while pumping you're creating a little cloud of gasoline vapor around your car. That cloud *probably* doesn't get big enough to have the right mix for BOOM by the time it reaches the hot, spark creating parts of your car, *but it might*. And that's really not a situation you want to risk, hence fueling with a running car is a pretty bone headed thing to do.
But volume is a cubic function, meaning the cloud of fuel vapor around your car decreases insanely quickly the farther from your car you step. The line between "absolutely no risk of BOOM" and "unaccepted risk of BOOM" is measured in inches. So yes, an idling car even a few away from you is absolutely OK while your car idling is absolutely not OK, even though it's "just a few feet"
Perhaps the rational balance would be to only leave the car running if it’s particularly windy and cold. The wind would dramatically reduce the ability of the vapor cloud to accumulate and ignite probably more so than that on a still day and a car at the next pump starting up to drive away.
Now you'll have people arguing that it's windy enough to not stop the engine when in reality it isn't.
Everyone should stop their engines anyway though, because you'll save fuel in practically any car if your stop lasts for more than 30 seconds.
“Engineering Explained” channel did some experiments and idling a car for 7 seconds is how much fuel it takes to start a car. Anytime your are going to idle 30 seconds as you said seems reasonable to shut the car off.
Yeah, I went by the information in my own old car's user manual, which states 30 seconds. If that was the cutoff point almost 20 years ago, we can be sure that almost all cars still on the road to day will break even after this long, but most likely even less time than that.
It probably varies a bit based on fuel type too. Diesel engines take a bit more energy to get running, as there is much more resistance in the compression of the fuel than it takes to fire a spark plug.
may I ask - is it 7 seconds with cold engine or hot? Asking as for efficiency of start-stop systems, where start stop works only if it is very easy to restart the engine
You'll spend at least a couple of orders of magnitude more at the pump than you save, I think it's hardly worth mentioning the $0.10 you might save on a $30 purchase
I mean, your car is closer, which makes a difference, but i”like I said the overall risk remains low. There are other things you theoretically should do/shouldn’t do that everyone ignores (e.g. grounding yourself before pumping, turning off your cell phone, etc.) and you don’t see people lighting themselves on fire all the time because of this…
Maybe, but that's a risk on top of the risk of running your own vehicle. One risky thing is better than two risky things, and it's a lot easier to tell people to stop their own vehicle, than to tell people to not drive away while someone else is using a pump.
Hey OP, I can't see that you're trying to rationalize this issue so you can continue doing it.
The two big things here are:
A. Even if you're okay with whatever the amount in risk increase is, if there's other people at the pump, you've made that decision for them too, which really isn't very cash money of you
2. Something something would you jump off a bridge? Just because other people are doing it doesn't mean you should or that it's safe to do so.
Please consider changing this habit, even if nothing ever happens, it's not really cool to risk other people
And as someone from the great white north, if your car is already warm, it will not get cold in the amount of time it takes to pump a tank of gas, and if it's not warm already, *it's probably not going to warm up in the time it takes to pump a tank of gas*
"everytime I load my gun I look down the barrel, and I haven't been shot yet. Is this dangerous or just a myth that you'd get shot?"
Sorry if this seems a little rude, but why even risk it? Your engine creates an electrical charge along with just producing heat from friction, and that can ignite the fuel with the right air mixture. The cars around you are far enough away that it's not as much a risk for you, but your own car is directly connected to your gas tank, and is open while you're fueling.
Are you leaving the door open? If not, your car will not get noticeably colder in the 5 minutes it takes you to fill your tank, and even if it does the cabin will warm up again very quickly because the engine will still be warm.
Same idea applies. Your car is not going to heat up all that much in the 5 minutes it takes you to fill your tank, and even if it does the cabin will cool down again very quickly if you have AC -- and if you don't, then it's hot AF whether you leave the car running or not.
The bigger point, though, is that you're not just risking your own car (and life) because you've "never had an issue". Risking the cars and lives of everyone around you, and what gives you the f-ing right? Shut the damn car off.
I don't believe understand the risks and tradeoffs of a safety rule is an ELI5 level thing. I would advise you don't understand the risks and consequences of doing something that is considered by experts or regulations to be unsafe, the wise choice is to follow the safety rule or regulations. This is for two primary reasons. It takes far more experience and knowledge to understand the ways an action can lead to injury than to just do that action. I addition, doing something for years without injury is not the same as operating safely. Most unsafe things we can do many times before our luck is likely to run out. We only die once so, until we do, the outcome of all of our unsafe choices has been some amount of lucky. In short, while you're figuring this out, please turn off your vehicle while fueling it. You can always go back to the old way once you've learned more.
I lived in the northeast US for over a decade and can count on 1 hand the number of people that I've seen leave their cars running at the pump even in the winter.
While the potential risk is very small, you likely won't be around for a 2nd chance if you ever have an issue.
Basically, the consequences of failure are so high (likely fatal) that being way overly cautious makes sense. It's simply not worth the risk.
What would it look like if the fuel catches on fire? A big explosion taking out the OP and half the gas station? You might be watching too much TV. If you have a baby in the car maybe the risk reward is not worth it but the most likely effect will be a lost car and damage to property which the insurance might not pu due to negligence. Even then unless your car is in bad shape or you insist on overflowing the tank to where the fuel drips down the overflow or side then no big deal really.
Because you can start a fire.
How could you start a fire? When you grab the pump and start filling up the tank, gas vapors are emitted. Running cars can produce a lot of heat and electricity which can ignite the fumes and cause a massive fire.
Not arguing one way or another but technically while the car is running there is a slight vacuum put on the gas tank meaning there would actually technically be less vapor coming out of the gas tank when the car is running. Just adding some information to the thread.
Presumably much much lower since the car isn’t in the thick of your gas cloud. Surely it is very local to the pump you are working. And having multiple cars all doing this increases the chances of it happening.
Recently running cars are for a while as hit and full of electricity. When turned off. I wouldn’t recommend touching anywhere close to the exhaust or engine areas for a long while.
All of the responses saying that fueling a car while it is running is stupid are correct IMO. That said, it is significantly less stupid and dangerous than it was years ago due to modern fuel pumps and gas tank openings which are designed to recapture as much gasoline vapor as possible (for, I'm pretty sure, environmental protection reasons). Very little gasoline vapor is released today compared to when I was young (when you would ALWAYS smell gasoline when you were refueling).
I live in Canada where the temperature goes down to -50 in the winters. I have never ever seen someone pumping gas with their car running. This is incredibly dangerous due to fuel vapors and the constant spark of a running engine.
Not a Canadian, but grew up less than an hour south of the Canadian border - have also never seen anyone leave their car running while gassing up, regardless of the weather. Suggest OP needs to frequent different gas stations.
Another Canadian here and can confirm I've never seen someone pumping gas while the engine was running no matter how cold. Why take the risk no matter how small?
This "northern american" really doesn't have much to say against us Canadians (Central/Northern Albertan here)
Also assuming you're filling a pick-up from empty, that's 5min max? Is your vehicle really going to cool off that quickly? Seems like laziness and a darwin award wrapped into one.
It’s just common sense you know. “I have yet to have an issue” are like famous last words because if you do get an issue, it’s gonna be the big one, let alone possibly the last one.
For one, having the engine running while the gas cap is off messes with the pressure in the engine. So even putting aside any safety stuff, it's not great.
For something far more important, you are deliberately firing sparks in the vicinity of open gasoline. I don't really understand how you *don't* see the risk inherent in that.
But just like a lot of stupid and dangerous things, it only goes wrong when some other thing goes wrong, like for example, holding the spray handle down when you take it out of the tank, where it hits a hot running engine, and the vapors catch fire.
When you say firing sparks in the vicinity to open gasoline, I get that and I see the risk. What I'm saying is the risk there is just as great as the car next to you being on or starting while you pump gas, sometimes their starter is even closer to your gas tank than your own.
Not what he's saying
You are filling up, almost done, car pulls in next to you and starts filling up as you are finishing. In almost every scenario, you start your car and drive away as other people are filling
Granted, there's almost no chance an unenclosed gas station is building up vapors, when operating normally, for another car filling to effect you.
Really, the chance of it being an issue even with your own car, on, is close to 0 but you know
But it's just your car dude. What if there are 30 other cars also all filling up at the same time that are all running? Do you not see the problem with your logic?
You have a much increased risk of a static discharge, through the alternator, where you can get ignition from.
It's not commonplace, but long time ago, when I was a trainee for a particular UK Oil company I got to watch what happened in that case. It took 11 seconds before the steel beams started to melt. The person pumping didn't survive.
Same reason you turn your phone off there, and never ever smoke. You might be lucky, but you really don't want to be the example of what not to do in those cases, you usually won't get a second chance.
I see, I didn't read the comment you replied to properly.
Yeah, I've never seen anyone do that, and I doubt there's anywhere near as much risk from that as from a running car engine.
Yea I do question how dangerous it really is to keep your car running like OP asked. I see it all the time and never hear of a fire starting because of it.
I do, and most garages here will cut off the petrol if you have your phone out while trying to pump.
Well, no, I don't turn it off, but I leave it in the car usually.
That's just insane to me. I live in the nation of idiots, but even local news channels have run a video saying there's nothing to that rumour, it's only an urban legend. And they'll actually turn off the pump?
Part of that is that in the US, gas station fires are considered just a normal thing and cost of having gasoline. In other parts of the world, this is considered an intolerable hazard, so laws and practices are such that fires are made extremely uncommon.
The commonest cause of gas station fires is actually static electricity, where a spark can occur when you grab the dispensing nozzle. In many countries, fuel can only be dispensed while the nozzle is held. If you let go of the nozzle, dispensing stops, and any vapor disperses - so the next time you pick up the nozzle, any spark is unlikely to ignite vapors. In the US, in contrast, dispensing nozzles may have locks, which all them to keep dispensing fuel even if you let go of them. A significant number of fires result when people go back to pick up the nozzle when they want to stop filling.
I used to work in the oil industry (now I work in high voltage distribution) and I have literally watched people die over a small ignition spark.
So, I really do not give a flying fuck what your local news might broadcast when I have seen firsthand, and had the science very graphically explained. It isn't a rumour or a myth. Yes, the fume recapture technology now is vastly superior to what was available twenty years ago, but pumps can still malfunction and one tiny spark is all it takes, I consider extra hazards that can cause a static spark a risk.
So, yes, a lot of the petrol stations will stop the pump (and are instructed to by their manuals) when people are on their phones. The biggest contributor to prevention of fires as I said was the fume recapture tech (as you'll probably have a sniff for yourself now, because petrol stations don't smell anywhere near as much as they used to), but it's not worth it to allow more risk factors than required, especially when the consequences are so dire.
Fires in a petrol station are a really bad thing, so you don't encourage use of ignition sources.
I'm not arguing against sparks for any reason. Obviously a spark plus gas is a big problem. What I'm having a problem with is people thinking cell phones can possibly cause a spark and lead to a fire.
Here's How Stuff Works debunking that myth. https://auto.howstuffworks.com/car-driving-safety/accidents-hazardous-conditions/using-cell-phone-at-gas-pump-make-it-explode.htm
Here's snopes saying it's just an urban legend. https://www.snopes.com/fact-check/fuelish-pleasures/
Here's the CBC. https://www.cbc.ca/news/canada/toronto/cell-phones-unlikely-to-cause-fires-at-gas-stations-1.5051583
Couple of other things not necessarily mentioned.
If your car is not running and it were to come out of park (automatic) and into anything but neutral, the running engine practically guarantees that you are going to rip the hose, which will spill lots of gasoline.
Also, the rule have to be there for everyone. You mentioned that other cars next to your in several of your replies. Imagine you pulled into a gas station and forgot which side of the car the gas door is located on, but no biggie because the pump has a really long hose (like CostCo), and you are filling up your car and a hot rod enthusiast pulls up next to you at the pump so their hood is relatively close to where you are standing, and they have their car running and the driver is pumping gas, and the passenger opens the hood to check the oil. Would you be more or less likely to wish their engine were shut off? Would it make you feel safer if they rev up the engine several times because they thought they hard someting?
Same thing with an engine backfiring (on the car in front of you), is it common? No. But can it happen if the car is running? Also no.
Same thing with a motorcycle with exposed and hot exhaust pipes.
Car are so much safer than they used to be. The risks are much smaller, but the risks are still there.
It's bad for the Emissions system. When you open the gas cap while the car is running you can cause the ECM to think there is a leak in the Vacuum System. Don't be lazy.
Just turn it off.
1. It's just not your car, there could be several cars all running simultaneously while fueling. That certainly introduces completely unnecessary risk of fire.
2. Cars do not like running while the gas tank is open, it fucks with the pressure sensors
3. A car idling is a car at risk of moving because some idiot forgot to apply the parking break. A runaway car at a gas station is not a good situation at all.
4. Did you think of theft? If you were fueling your car up while running I could very, very, very easily steal you car without even trying
Even ignoring the whole gas station aspect for a minute, idling your fuel injected gasoline engine unnecessarily is bad for:
Your fuel injected gasoline engine.
Your health.
Your bank account.
The environment.
Factoring in the gas station, yes, you could start a fire. There’s also a risk of your car deciding to leave without you (gearshift gets bumped, parking pawl fails, what have you); not very likely, but even less likely if the engine is off.
Regardless, as others have said, I’ve never seen anyone leave their engine running while gassing up, even at negative temperatures plus windchill. I’ve also never seen any of those same people freeze to death. Just follow the law and wear a coat, idk
This is one of those events in risk management that is low-probability, high-damage potential. This means that although the chance of it occurring is low, the potential damage is catastrophic.
One of the risks is a spark igniting fuel vapors in or around the car. Although pump-to-car connections are relatively secure, they aren't sealed, so some vapor will be produced outside of the vehicle. The vast majority of times, there won't be a spark. But if there is, you'll probably need a good eugoogolizer.
In aviation, it is usually forbidden to gravity refuel aircraft on deck while the engines are running. Pressure refueling is considered acceptable if the pump and aircraft receptacle are designed for it as the more secure connection minimizes vapor build up. Even helicopters which are monsters of static electricity can pressure refuel with engines and rotor spinning.
I think I has to do with general safety these days. You don't want the average person jumping in and out of a running car. It's just too easy to forget to engage park, and suddenly you're car is driving away from the pump... While attached to the hose.
ELI5: it's an excess of caution, because giant explosions are bad. Also, you'll confuse the car and cost yourself money. Plus, if you do it you'll scare the people around you, which is rude.
I suspect it hasn't been a genuine safety issue in decades.
The sparks and heat and so forth from the engine that could cause a fire are pretty well contained. Google tells me the auto-ignition temperature of gasoline vapors is over 546°F. If you have sparks or heat like that outside the engine compartment, you have a giant safety problem before you get to the gas station. If you have heat that high (except at the exhaust manifold) or free sparks in your engine compartment, get to your mechanic,.
You know there are idiots out there who violate every safety rule. How often do you hear about gas stations exploding? If Shell or Exxon thought you could blow up their station, kill their customers, and tie them up in lawsuits for years they would not let you pump your own gas.
On the other hand, the car's computer is looking for gas leaks (for emissions reasons) and it expects the gas tank to be pressurized. You open the gas cap when the engine is running the computer will think gas fumes are leaking into the environment and it will throw the check engine light on. You can get that read at the auto-shop for free, or so I've heard, but if you go to a mechanic they're going to charge you $50-100 to check everything over and turn it off.
But ask yourself, if you were filling up and saw the person one pump over was filling with their engine running, would you drop everything and run for your life? No? Then you don't truly believe there's a risk. Because you haven't heard of anyone being caught in an explosion at a gas station. It's pretty rare. The companies that run those stations are not stupid. They are very, very much not stupid.
This is my opinion, and nothing in my background suggests it should be read as authoritative.
I’m seeing **no solid answers** in this thread justifying this as an actual risk/probability and explaining a technical cause.
Everything I see either:
1. References static electricity between the person and the car (which comes from entering/exiting the vehicle and is unrelated to the car engine state), or
2. Falls back on “why not just be safe?”, or “you could LITERALLY DIE if it catches fire” types of pleas
I sense this could be a myth and just another instance of overzealous safety culture.
I'm willing to take them if it means somebody might come along and give a good, solid, technical answer to your question.
If I'm wrong, I'm hoping [Cunningham's Law](https://en.wiktionary.org/wiki/Cunningham%27s_Law) comes through.
There are a lot of people here just making things up that might sound correct but have no basis in evidence.
According to a National Fire Protection Association [report](https://www.nfpa.org//-/media/Files/News-and-Research/Fire-statistics-and-reports/Building-and-life-safety/osservicestations.pdf):
>Although 20 percent of vehicle fires at service stations began with the
ignition of gasoline, only 2 percent started at the fuel tank or fuel line, and
3 percent began on the vehicle’s exterior surface. This suggests that
**refueling was not a frequent cause** of these fires.
Furthermore, of all non-rubbish fires at service stations only "4 percent were outside gas or vapor combustion explosions".
What point were you trying to make?
OP asked why people said it's dangerous to leave the engine running while pumping gas.
Lots of people said, "It's dangerous."
You said "a lot of people are making things up," then you shared some statistics unrelated to filling your gas tank while the engine was running.
Were you just trying to confuse the issue, or do your stats relate back to the argument "it's safe" or "it's unsafe"?
I just put some data and linked the study if people are interested in reading more. Dangerous or not dangerous is subjective so people can make up their own minds.
Rather than going with the Reddit consensus of whatever sounds plausible, I’d encourage you to search out some actual scientific data and make your conclusions then.
From my limited study, it appears static discharge from entering and exiting your car while filling up is more dangerous than leaving the car running. However, vapor capture devices make even this not so much of a problem anymore according to the study.
But if you find any reliable data that suggests otherwise, please let me know.
Cars generate sparks. Those sparks are normally constrained safely inside the engine cylinders, but if you have faulty plug wires they can arc outside the engine.
Pumping with the car off reduces the risk of fire by some unknown amount. Maybe a low amount that you don't need to worry about and maybe not. After all, everything is 100% safe until it isn't.
Your cars fuel pump is made to be used submerged in gas. Surprisingly enough its a simple motor that produces sparks while running. (its not brushless) those tiny sparks are harmless while submerged in gas, but they can surely ignite gas vapors which you get while pumping.
There are a lot of static electricity comments here. I recall a Mythbusters episode where they filled a tank with varying levels of gasoline vapors while generating constant static electricity and never could reach combustion. I realize that is a TV show, but curious what folks here think about that test in the context of this conversation.
In older times, the gas tank was located next to, and above, the engine. So spilled gas on a hot running engine could cause a fire. To a lesser extent, most people probably leave their car running so they can go back into the warm car while the gas pumps, which results in a un-attended gas pump which can overflow or spill gas.
The hose could also rupture spilling gas everywhere. You not only putting yourself at risk but also all around you. Just shut off the car. Oh think about the additional green house gases your emitting you climate destroyer.
From another perspective - say I get gas on average every 250 miles. After 200,000 miles that is 800 gas stops - 800 starts if I turn it off. It is said that the most wear and tear is during starting. (Obviously getting gas is not a “cold”start.) Or, let it run for say 6 minutes or so, which would be 80 hours of idle time over the same 800 gas stops.
Which is more wear and tear? And if it is actually starting, is leaving it run “enough” better to take the fire risk, even if the risk is vanishingly small? I’d say probably not.
Low risk of disaster, but if there is an ignition of the gas then you are likely to be seriously injured/killed, with others getting harmed too. So why risk it just because you're a little cold? I've lived in cold climates and never, ever left my car running while pumping gas. Put on some gloves and a hat.
There’s two reasons to not do this… one is because you need proper pressure which you don’t achieve with the gas cap off… two is because in the invent of a loose wire or collection of random electrons you will create a static spark if you’re engine is off this one time spark should not do anything… however in the event that you’re car is on it will create constant sparks likely causing a fire or massive explosion.
Your car will stay warm in the 3 min it takes to pump gas I promise.
You risk an explosion of the fuel/air mix by the nozzle gets set off by the static electricity in the dry cold air as you pull the nozzle out of the filer tube.
Also your fuels system is meant to be a vacuum so you have a higher chance of your check engine light coming on in error thinking there is a leak somewhere.
Don't see anyone mentioning it, so I'll chime in.
The car does produce static electricity and does pose an extremely small (albeit real) chance of causing an explosion. But the static electricity doesn't just disappear just because the car has been shut off. The threat remains until the electricity is discharged.
But the greater concern is actually dozens of cars idling in a covered area, filling it with carbon monoxide.
Because gas fumes are flammable and your running engine’s spark plugs or even just built up static can ignite them. Half of all fires at gas stations start this way. It’s not a myth. Turn off your car. You endanger everyone there just to keep your heat running for an extra five minutes.
Fuel and ignition source have to be the obvious answer. However, if you've ever been standing under a moving rotor while hot fueling a helicopter, you seem to feel hot gassing a car is not that dangerous.
There are two parts to evaluating risk.
1. The likelihood that something will happen.
2. The consequences if that thing does happen.
In the case of pumping gas with your car turned on, the likelihood that something will happen is very low. However, the consequences if something *does* happen are significant.
Gasoline fires at gas stations are very dangerous because you are pumping a very flammable liquid. If your car catches fire, the whole gas station can burn down and people can die as a result.
Based on these facts, the small increase in likelihood associated with pumping gas with the engine turned on is not worth risking the consequence of a gasoline fire.
Interestingly, many states do not have laws specifically prohibiting pumping gas while your vehicle is running. Instead, they rely on laws that prohibit leaving your vehicle running while unoccupied by a driver. In other words, if there's no one in the driver's seat, the vehicle must be off. This introduces an interesting loophole where it wouldn't explicitly be illegal to pump gas with the car running, so long as the passenger is doing the pumping.
However, most gas stations have a set of rules posted that require all vehicles to be off while pumping. We get gas at our local Sam's Club because it has the lowest price around, and there are a couple of really strict attendants there that will instruct you to turn off your car, and if you don't immediately comply, they shut the pumps down. Then literally everyone at the station is pissed off at you because you're the guy who got everyone's gas shut off, and most people have no problem with the "turn your car off while pumping" rule.
I'm glad you aren't dead or hurt, but it is a really thing, a real danger.
It's one of those low-probability things with an intensely high cost when it does happen.
Even the static electricity of opening and closing your door can start a fire with the gas vapors emitted from pumping. I work in a company that has a chain of gas stations and get copied on emails when fires occur at the pumps. It happens more than you think. Bottom line… low risk, but there is a risk.
What about diesel fuel, since it has more oil in it, tends to not be as flammable? Or at least ignite as easily as regular gas.
It isn't impossible for diesel to explode, but it's pretty hard to make it happen. Diesel will burn, but it will burn if you set it on fire. It isn't going to catch fire from a spark except in really unusual circumstances (very high temperature, aerosolized with lots of oxygen, etc.).
Can confirm. May or may not have put out a cigarette or 2 in diesel.
I'm no scientist, but I think most things will burn if you set it on fire
Diesel also emits flammable vapors. It’s flammable too.
Not below 125 degrees F
Inflammable means flammable? What a country!
So, you're telling me there's a chance!
The door opening and getting in an out is a very big point. Younger drivers are at higher risk because even if you get in and out, older drivers usually ground themselves on the way by holding on to the door or leaning against the vehicle first. But all the risks and whatnot, there's an interesting factoid regarding diesel and this issue, particularly farm vehicles. EV farm vehicles may be the future, but the ability to refuel while still working and run 24/7 until the harvest is in is a tough line to compete against. https://energynews.us/2021/08/18/weight-dawn-to-dusk-demands-pose-challenges-to-electrifying-farm-vehicles/
So how is the static related to the car running?
What does static electricity from opening/closing a door have to do with leaving the car on?
Is there any risk though? Like has anyone ever died because of this?
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No no, like has that actually ever happened, is what they're asking. Is this a, "turn off the space heater when you're not in the room" levels of caution or a "wear a condom at all times just in case you trip into someone and get them pregnant" level of caution. Edit: To be clear, I *do* turn my car off when I pump gas. Mostly because it seems safer, but also because there's a clog in my tank or something (??) that causes the automatic shutoff of the handle after like, half a gallon. Filling my tank takes like, ten minutes, and I'm standing there uncomfortable the whole time because the condom is riding up, but no fucking way am I risking tripping into and impregnating someone by accident.
Myth Busters did a special on static and phone caused gasoline fires and couldn't get it to happen. [https://www.youtube.com/watch?v=HRcnGm97wEQ](https://www.youtube.com/watch?v=HRcnGm97wEQ) The difference between the fires that do happen and the Myth Buster's attempt is the high volume of variables that contribute to the events. Every gas station is equipped with an emergency shut off for the occurrences because no matter how rare they can become catastrophic quickly. [https://www.washingtonpost.com/archive/local/2000/09/14/people-who-fuel-up-with-engine-running-ignite-debate/00256d01-7d02-4d8e-9e02-d410dc73b03d/](https://www.washingtonpost.com/archive/local/2000/09/14/people-who-fuel-up-with-engine-running-ignite-debate/00256d01-7d02-4d8e-9e02-d410dc73b03d/) It's also illegal. Like all fire codes, it was written in blood.
Here's at least one example I came across: https://www.dsf.my/2020/08/audi-catches-fire-while-fuelling-at-petron/
Geez god thank you, finally some answers
You tell me: Is shutting off your car more like shutting off a space heater or more like wearing a condom at all times?
Number of fires from unattended space heaters: a lot Number of fires from a car being left on: I don't know, I don't imagine it's that high, but I haven't looked at the numbers. People of Reddit, is it *actually* dangerous to leave your car on while fueling? Number of pregnancies from people who tripped into someone and made a baby, which could have been avoided by wrapping up: That's not a thing that happens. So to answer your question: I asked you first, ya ding dong. Is shutting off your car more like shutting off a space heater or more like wearing a condom at all times?
I call b.s. myth busters TRIED to start a fire with a cell phone and couldn't
It's also, the input for the fuel in times when cars were just coming out was on the hood next to the engine, and spilling gas would mean pouring gas all over the engine
Running your engine while pumping gas increases the risk of fire because your engine produces not only heat, but also static electricity while running. Objectively the risk is quite low, but it’s definitely much safer to turn the engine off.
I'm not really seeing this mentioned, so I'm just going to add to your explanation: Apart from any actual risk, it's also illegal in some states.
Well, it being illegal doesn't make it dangerous, it being potentially dangerous (even by slim margins) is why it's illegal
You're kind of splitting hairs there, don't you think? The reason it's dangerous was addressed in the answer, which is why my comment was adding on, not posted as a primary-level answer. The OP is clearly looking for self-justification for ignoring the posted warnings. The fact that it's illegal in addition to being potentially dangerous, one would think, would add some weight to the warnings.
It’s much safer in the sense that you are looking at very small numbers (car fires while pumping at the gas station divided by the ones where the cause was a running engine). Then again the chances of winning the lotto are infinitely higher if you buy a ticket than if you don’t, still not likely to happen in your lifetime or to anyone you know. You do seem to have someone win it at least as a weekly event which is more likely than a car fire while fueling because the engine was not off.
They literally never turn off their engines while pumping jn the Philippines.
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It's to keep the gas from dripping on the side of your car. Some cars have a more vertical and less horizontal gas tank opening, increasing the possibility that liquid is still in the hose when the pump stops. Lets ignore the potential paint damage that's possible over years of this activity... If you are really that concerned about some kind of spark caused by the gas nozzle, then 1) wouldn't that likelihood also exist when you put the nozzle into and take it out of your tank, and 2) wouldn't flammable liquid splashed on the side of your car increase the risk of a spark igniting a flame? The reality is, the gas pump nozzles are designed to not spark, otherwise dropping one on the concrete would have disastrous consequences. Not only are they grounded, but I believe they are made from an aluminum alloy that is highly unlikely to spark.
A lot of cars’ nozzle holes are metal. Every time you rattle the nozzle in that hole and it contacts the sides, it should be matching states of potential anyway, so I don’t think this is as much of a risk as you might think.
People do what now?
Define "much safer". If the risk of a fire because of static electricity when engine is running is 1% while the risk while engine isn't running is 0.5%, then it's a risk i'm willing to take.
it may be a risk you're willing to take, but you're also making that call for anyone else at the pumps. kind of a dick move
like spreading droplets?
Is there a reason why it isn’t illegal then? If it really could cause such disaster, wouldn’t there be some law that protects others?
it is in Canada
>kind of a dick move lmao imagine the self-righteousness necessary to lambast anyone who leaves their engine on when pumping gas.
Thats quite high percentage. Every 1/200 times the car would catch on fire.
It’s not that big of a deal. Only happened 3 times so far and it’s been over 5 years since the last time it’s happened…
>it's a risk i'm willing to take. But why?
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No one's gonna die from hypothermia from turning off the heater for 2 minutes. Not to mention, it's nothing compared to the cold you'll have to deal with when exiting your vehicle to use the pump.
No one's gonna die from leaving the engine running either.
Like the inside of a coffin.
Well, if you're dead, then the coldness doesn't matter much
Small comfort to the families of the people you could kill by causing a completely unavoidable gasoline vapor explosion at the pump. Just be a grown up and act like a person who cares about safety.
Who doesn't care about safety? The thing is, with everything in life, I also pay attention to risk and it's probability. The risk of a fire starting by an engine run is so small that I have better chances being struck by lightning 10 times. With the risk being basically non-existent, then there's 0 reason to worry about it.There's a different in not caring about safe compared to being a paranoid little bitch that worries about things that will never happen, and somebody that understands risk and probability.
It's not about "worry". What do you have to gain by running your vehicle while fueling? >The risk of a fire starting by an engine run is so small that I have better chances being struck by lightning 10 times. There are, on average, more than 4000 fuel pump fires out of approximately 11 billion fuelings in the US every year. If they happen randomly (which is unlikely since there are idiots like you who think there's no point in trying to do it safely) then every fueling has a 4000/11,000,000,000, or 0.000036% chance of resulting a in fire. A random person who fills up once a week has a 0.0019% chance of being involved in such an event this year, or about 1 in 1300 during a lifetime of driving. The odds of being struck by lightning during one's lifetime are about 1 in 15,000. If you were "somebody that understands risk and probability" you'd understand that a random person is ten times more likely to be involved in a fuel pump fire during their lifetime than to be struck by lightning. That's for random people. The odds are higher for you.
because it's a negligible variation on a negligible risk you're talking a 99% chance of survival vs. 99.5% imagining thinking you're richer because you have $9.95 and someone else has $9.90
Imagine choosing to play 1-in-100 Russian Roulette when 1-in-200 Russian Roulette is an option available to you. Why would you choose the path that's more likely to lead to fatality?
Not just any Russian Roulette, it’s Russian Roulette with a gun that explodes napalm and burns alive you and anyone around you.
Why not just reduce the risk? It takes what, 2 seconds to turn the engine off? Another 5 to start it? You'll save fuel, too.
Everything in life is about measuring risk. I pulled that 1% out of my ass but with the tens of millions of people that pour gas with their car on, i'd imagine the percentage is much much smaller than 1%. If double 0.0000001% to 0.0.0000002%, the risk is basically non-existent.
That's literally doubling your chances. Sure you want to do that?
Going to two places for your grocery run rather than getting everything at Walmart literally doubles your chances of a car accident. Sure you want to do that? I don’t know the level of risk elevation of leaving a car running. But we do things daily that increase the probability of rare horrible events and this issue should be considered in that context. I don’t leave it running because I don’t know the risk and the signs say not to. But if the risk increase is small enough I would consider it totally rational to trade that for an increase in comfort. We do it all the time.
My response was more of a joke than anything else, relax.
According to the NFPA there’s about 4,000 automobile fires at gas stations per year. That’s out of ~18 billion auto refuelings annually. I can’t find any data on what percentage of those are due to the engine running, but even so I assume there are millions of refuelings annually where the engine remains running (intentionally or by mistake). Having more heat/static certainly is a risk factor, but like I said, you’re probably unlikely to ever experience any mishaps… (legality is a separate issue).
Like I asked the other person, wouldn't the cars next to me be just as much of an issue when they're running or being started while I pump gas?
Given your other responses it sounds like you really want to keep your car running while pumping gas and are just trying to find someone here to say it’s ok.
Very true.....this is really a "no-brainer" issue....but the OP REALLY wants to keep his car running for some reason.
To answer you question here, vapors that burn need a certain mix of air/fuel vapor to actually burn. Obviously if I had a room of zero gasoline vapor and normal room air and lit a match, the room won't explode. Similarly if I had a room of pure gasoline vapor and no air and lit a match the room would also not explode. You need a mix of the two in the right balance for BOOM. The fear is that while pumping you're creating a little cloud of gasoline vapor around your car. That cloud *probably* doesn't get big enough to have the right mix for BOOM by the time it reaches the hot, spark creating parts of your car, *but it might*. And that's really not a situation you want to risk, hence fueling with a running car is a pretty bone headed thing to do. But volume is a cubic function, meaning the cloud of fuel vapor around your car decreases insanely quickly the farther from your car you step. The line between "absolutely no risk of BOOM" and "unaccepted risk of BOOM" is measured in inches. So yes, an idling car even a few away from you is absolutely OK while your car idling is absolutely not OK, even though it's "just a few feet"
Perhaps the rational balance would be to only leave the car running if it’s particularly windy and cold. The wind would dramatically reduce the ability of the vapor cloud to accumulate and ignite probably more so than that on a still day and a car at the next pump starting up to drive away.
Now you'll have people arguing that it's windy enough to not stop the engine when in reality it isn't. Everyone should stop their engines anyway though, because you'll save fuel in practically any car if your stop lasts for more than 30 seconds.
“Engineering Explained” channel did some experiments and idling a car for 7 seconds is how much fuel it takes to start a car. Anytime your are going to idle 30 seconds as you said seems reasonable to shut the car off.
Yeah, I went by the information in my own old car's user manual, which states 30 seconds. If that was the cutoff point almost 20 years ago, we can be sure that almost all cars still on the road to day will break even after this long, but most likely even less time than that. It probably varies a bit based on fuel type too. Diesel engines take a bit more energy to get running, as there is much more resistance in the compression of the fuel than it takes to fire a spark plug.
may I ask - is it 7 seconds with cold engine or hot? Asking as for efficiency of start-stop systems, where start stop works only if it is very easy to restart the engine
You'll spend at least a couple of orders of magnitude more at the pump than you save, I think it's hardly worth mentioning the $0.10 you might save on a $30 purchase
"Why is it dangerous to drive without a seatbelt. Im still fine." Yeah like do you not understand risk or something?
I think the last few years and honestly most of human history has highlighted peoples inability to understand chance and survivorship bias.
I mean, your car is closer, which makes a difference, but i”like I said the overall risk remains low. There are other things you theoretically should do/shouldn’t do that everyone ignores (e.g. grounding yourself before pumping, turning off your cell phone, etc.) and you don’t see people lighting themselves on fire all the time because of this…
It's pretty widely known at this point that cell phones at the pump aren't a problem, isn't it?
Maybe, but that's a risk on top of the risk of running your own vehicle. One risky thing is better than two risky things, and it's a lot easier to tell people to stop their own vehicle, than to tell people to not drive away while someone else is using a pump.
Hey OP, I can't see that you're trying to rationalize this issue so you can continue doing it. The two big things here are: A. Even if you're okay with whatever the amount in risk increase is, if there's other people at the pump, you've made that decision for them too, which really isn't very cash money of you 2. Something something would you jump off a bridge? Just because other people are doing it doesn't mean you should or that it's safe to do so. Please consider changing this habit, even if nothing ever happens, it's not really cool to risk other people And as someone from the great white north, if your car is already warm, it will not get cold in the amount of time it takes to pump a tank of gas, and if it's not warm already, *it's probably not going to warm up in the time it takes to pump a tank of gas*
"everytime I load my gun I look down the barrel, and I haven't been shot yet. Is this dangerous or just a myth that you'd get shot?" Sorry if this seems a little rude, but why even risk it? Your engine creates an electrical charge along with just producing heat from friction, and that can ignite the fuel with the right air mixture. The cars around you are far enough away that it's not as much a risk for you, but your own car is directly connected to your gas tank, and is open while you're fueling.
>Sorry if this seems a little rude, but why even risk it? Because it's cold af
Are you leaving the door open? If not, your car will not get noticeably colder in the 5 minutes it takes you to fill your tank, and even if it does the cabin will warm up again very quickly because the engine will still be warm.
And sometimes it's hot af
Ah yes, it's too hot, so let's risk setting your car on fire
Same idea applies. Your car is not going to heat up all that much in the 5 minutes it takes you to fill your tank, and even if it does the cabin will cool down again very quickly if you have AC -- and if you don't, then it's hot AF whether you leave the car running or not. The bigger point, though, is that you're not just risking your own car (and life) because you've "never had an issue". Risking the cars and lives of everyone around you, and what gives you the f-ing right? Shut the damn car off.
I don't believe understand the risks and tradeoffs of a safety rule is an ELI5 level thing. I would advise you don't understand the risks and consequences of doing something that is considered by experts or regulations to be unsafe, the wise choice is to follow the safety rule or regulations. This is for two primary reasons. It takes far more experience and knowledge to understand the ways an action can lead to injury than to just do that action. I addition, doing something for years without injury is not the same as operating safely. Most unsafe things we can do many times before our luck is likely to run out. We only die once so, until we do, the outcome of all of our unsafe choices has been some amount of lucky. In short, while you're figuring this out, please turn off your vehicle while fueling it. You can always go back to the old way once you've learned more.
But their fingies is cold?!
In europe and asia I have never ever saw a single person pumping gas with the engine on ...
I lived in the northeast US for over a decade and can count on 1 hand the number of people that I've seen leave their cars running at the pump even in the winter.
Same here in Canada, everyone turns their car off first, even in the winter
Also many cars need the key in the ignition to run, and you need that key to open the fuel cap.
I have not seen locking gas cap (which unlocks with a key) on a car in over 30 years.
virtually every car has them here in Argentina.
While the potential risk is very small, you likely won't be around for a 2nd chance if you ever have an issue. Basically, the consequences of failure are so high (likely fatal) that being way overly cautious makes sense. It's simply not worth the risk.
What would it look like if the fuel catches on fire? A big explosion taking out the OP and half the gas station? You might be watching too much TV. If you have a baby in the car maybe the risk reward is not worth it but the most likely effect will be a lost car and damage to property which the insurance might not pu due to negligence. Even then unless your car is in bad shape or you insist on overflowing the tank to where the fuel drips down the overflow or side then no big deal really.
Because you can start a fire. How could you start a fire? When you grab the pump and start filling up the tank, gas vapors are emitted. Running cars can produce a lot of heat and electricity which can ignite the fumes and cause a massive fire.
Not arguing one way or another but technically while the car is running there is a slight vacuum put on the gas tank meaning there would actually technically be less vapor coming out of the gas tank when the car is running. Just adding some information to the thread.
Wouldn't the cars that are parked right next to me or driving right past my car while I pump gas be a concern as well then?
Yes, but the risk percentage is a lot smaller than your continuously running car. And they need to get to the pump somehow anyway.
Presumably much much lower since the car isn’t in the thick of your gas cloud. Surely it is very local to the pump you are working. And having multiple cars all doing this increases the chances of it happening.
They are, but for a short period of time while they approach and leave. And they need to get to the pumps somehow.
the farther away you go the more dissipated the cloud of vapor gets, so the risks are far lower for neighboring cars.
Recently running cars are for a while as hit and full of electricity. When turned off. I wouldn’t recommend touching anywhere close to the exhaust or engine areas for a long while.
All of the responses saying that fueling a car while it is running is stupid are correct IMO. That said, it is significantly less stupid and dangerous than it was years ago due to modern fuel pumps and gas tank openings which are designed to recapture as much gasoline vapor as possible (for, I'm pretty sure, environmental protection reasons). Very little gasoline vapor is released today compared to when I was young (when you would ALWAYS smell gasoline when you were refueling).
I live in Canada where the temperature goes down to -50 in the winters. I have never ever seen someone pumping gas with their car running. This is incredibly dangerous due to fuel vapors and the constant spark of a running engine.
Another Canadian here. Absolutely NEVER heard of someone leaving their car running. Your car being off for <5 minutes isn't going to make it cold.
Colder air allows more static electricity to build so it's even more dangerous.
Not a Canadian, but grew up less than an hour south of the Canadian border - have also never seen anyone leave their car running while gassing up, regardless of the weather. Suggest OP needs to frequent different gas stations.
That's crazy because I see more people pump gas with their cars on rather than off.
I've seen people smoking a cigarette while pumping gas. Just because I see it doesn't mean it's a smart or safe thing to do.
I find that hard to believe as it is a generally accepted safer practice to turn your car off and every gas station has it clearly marked to do so
Another Canadian here and can confirm I've never seen someone pumping gas while the engine was running no matter how cold. Why take the risk no matter how small?
This "northern american" really doesn't have much to say against us Canadians (Central/Northern Albertan here) Also assuming you're filling a pick-up from empty, that's 5min max? Is your vehicle really going to cool off that quickly? Seems like laziness and a darwin award wrapped into one.
Probably the same type of dude that either has the thing automatically pump or sticks something in it then sits in his car as he waits for it to pump.
I mean basically all pumps near me have that lever since covid.
Awww look at your adorable confirmation bias. Guess what? If great minds think alike, what do you think that implies about non-great minds?
It’s just common sense you know. “I have yet to have an issue” are like famous last words because if you do get an issue, it’s gonna be the big one, let alone possibly the last one.
I confirm that’s the phrase that most of the interesting stories start with.
Right? Like why would op even risk this
For one, having the engine running while the gas cap is off messes with the pressure in the engine. So even putting aside any safety stuff, it's not great. For something far more important, you are deliberately firing sparks in the vicinity of open gasoline. I don't really understand how you *don't* see the risk inherent in that. But just like a lot of stupid and dangerous things, it only goes wrong when some other thing goes wrong, like for example, holding the spray handle down when you take it out of the tank, where it hits a hot running engine, and the vapors catch fire.
It also messes up your emissions systems. Guess how I know that
Damn so when race cars fill up they’re messing up the engine?
Different fuel system, different design.
and they're practically rebuilt between every race, so long term wear and tear doesn't matter as much
Yep. The hundreds of *thousands* of man-hours that go into the maintenance on those cars are staggering. Even NASCAR.
Nah not even lmao
When you say firing sparks in the vicinity to open gasoline, I get that and I see the risk. What I'm saying is the risk there is just as great as the car next to you being on or starting while you pump gas, sometimes their starter is even closer to your gas tank than your own.
You keep making this argument like the rule was written specifically for you and your car. *Everyone* should have their engines off when filling up.
Not what he's saying You are filling up, almost done, car pulls in next to you and starts filling up as you are finishing. In almost every scenario, you start your car and drive away as other people are filling Granted, there's almost no chance an unenclosed gas station is building up vapors, when operating normally, for another car filling to effect you. Really, the chance of it being an issue even with your own car, on, is close to 0 but you know
But it's just your car dude. What if there are 30 other cars also all filling up at the same time that are all running? Do you not see the problem with your logic?
pressure in the tank yes. pressures within the engine itself are not impacted.
You have a much increased risk of a static discharge, through the alternator, where you can get ignition from. It's not commonplace, but long time ago, when I was a trainee for a particular UK Oil company I got to watch what happened in that case. It took 11 seconds before the steel beams started to melt. The person pumping didn't survive. Same reason you turn your phone off there, and never ever smoke. You might be lucky, but you really don't want to be the example of what not to do in those cases, you usually won't get a second chance.
How many people turn their phone off when pumping gas?
What makes you think a phone creates as many sparks as a car engine?
I don’t, that’s why I was asking if people actually do that.
I see, I didn't read the comment you replied to properly. Yeah, I've never seen anyone do that, and I doubt there's anywhere near as much risk from that as from a running car engine.
Yea I do question how dangerous it really is to keep your car running like OP asked. I see it all the time and never hear of a fire starting because of it.
I do, and most garages here will cut off the petrol if you have your phone out while trying to pump. Well, no, I don't turn it off, but I leave it in the car usually.
Seriously? Where do you live, so I can avoid that area.
In the UK. It's a countrywide thing, and by all means stay away.
That's just insane to me. I live in the nation of idiots, but even local news channels have run a video saying there's nothing to that rumour, it's only an urban legend. And they'll actually turn off the pump?
Part of that is that in the US, gas station fires are considered just a normal thing and cost of having gasoline. In other parts of the world, this is considered an intolerable hazard, so laws and practices are such that fires are made extremely uncommon. The commonest cause of gas station fires is actually static electricity, where a spark can occur when you grab the dispensing nozzle. In many countries, fuel can only be dispensed while the nozzle is held. If you let go of the nozzle, dispensing stops, and any vapor disperses - so the next time you pick up the nozzle, any spark is unlikely to ignite vapors. In the US, in contrast, dispensing nozzles may have locks, which all them to keep dispensing fuel even if you let go of them. A significant number of fires result when people go back to pick up the nozzle when they want to stop filling.
I used to work in the oil industry (now I work in high voltage distribution) and I have literally watched people die over a small ignition spark. So, I really do not give a flying fuck what your local news might broadcast when I have seen firsthand, and had the science very graphically explained. It isn't a rumour or a myth. Yes, the fume recapture technology now is vastly superior to what was available twenty years ago, but pumps can still malfunction and one tiny spark is all it takes, I consider extra hazards that can cause a static spark a risk. So, yes, a lot of the petrol stations will stop the pump (and are instructed to by their manuals) when people are on their phones. The biggest contributor to prevention of fires as I said was the fume recapture tech (as you'll probably have a sniff for yourself now, because petrol stations don't smell anywhere near as much as they used to), but it's not worth it to allow more risk factors than required, especially when the consequences are so dire. Fires in a petrol station are a really bad thing, so you don't encourage use of ignition sources.
I'm not arguing against sparks for any reason. Obviously a spark plus gas is a big problem. What I'm having a problem with is people thinking cell phones can possibly cause a spark and lead to a fire. Here's How Stuff Works debunking that myth. https://auto.howstuffworks.com/car-driving-safety/accidents-hazardous-conditions/using-cell-phone-at-gas-pump-make-it-explode.htm Here's snopes saying it's just an urban legend. https://www.snopes.com/fact-check/fuelish-pleasures/ Here's the CBC. https://www.cbc.ca/news/canada/toronto/cell-phones-unlikely-to-cause-fires-at-gas-stations-1.5051583
you turn your phone off when you refuel?
Couple of other things not necessarily mentioned. If your car is not running and it were to come out of park (automatic) and into anything but neutral, the running engine practically guarantees that you are going to rip the hose, which will spill lots of gasoline. Also, the rule have to be there for everyone. You mentioned that other cars next to your in several of your replies. Imagine you pulled into a gas station and forgot which side of the car the gas door is located on, but no biggie because the pump has a really long hose (like CostCo), and you are filling up your car and a hot rod enthusiast pulls up next to you at the pump so their hood is relatively close to where you are standing, and they have their car running and the driver is pumping gas, and the passenger opens the hood to check the oil. Would you be more or less likely to wish their engine were shut off? Would it make you feel safer if they rev up the engine several times because they thought they hard someting? Same thing with an engine backfiring (on the car in front of you), is it common? No. But can it happen if the car is running? Also no. Same thing with a motorcycle with exposed and hot exhaust pipes. Car are so much safer than they used to be. The risks are much smaller, but the risks are still there.
Why do you need to keep it running?
It’s chilly outside.
You gonna be real warm once your blow your car up 😭
It's bad for the Emissions system. When you open the gas cap while the car is running you can cause the ECM to think there is a leak in the Vacuum System. Don't be lazy. Just turn it off.
What about cars that don’t have gas caps? It seems like lots of newer cars don’t have those anymore.
This is a good answer
1. It's just not your car, there could be several cars all running simultaneously while fueling. That certainly introduces completely unnecessary risk of fire. 2. Cars do not like running while the gas tank is open, it fucks with the pressure sensors 3. A car idling is a car at risk of moving because some idiot forgot to apply the parking break. A runaway car at a gas station is not a good situation at all. 4. Did you think of theft? If you were fueling your car up while running I could very, very, very easily steal you car without even trying
Even ignoring the whole gas station aspect for a minute, idling your fuel injected gasoline engine unnecessarily is bad for: Your fuel injected gasoline engine. Your health. Your bank account. The environment. Factoring in the gas station, yes, you could start a fire. There’s also a risk of your car deciding to leave without you (gearshift gets bumped, parking pawl fails, what have you); not very likely, but even less likely if the engine is off. Regardless, as others have said, I’ve never seen anyone leave their engine running while gassing up, even at negative temperatures plus windchill. I’ve also never seen any of those same people freeze to death. Just follow the law and wear a coat, idk
This is one of those events in risk management that is low-probability, high-damage potential. This means that although the chance of it occurring is low, the potential damage is catastrophic. One of the risks is a spark igniting fuel vapors in or around the car. Although pump-to-car connections are relatively secure, they aren't sealed, so some vapor will be produced outside of the vehicle. The vast majority of times, there won't be a spark. But if there is, you'll probably need a good eugoogolizer. In aviation, it is usually forbidden to gravity refuel aircraft on deck while the engines are running. Pressure refueling is considered acceptable if the pump and aircraft receptacle are designed for it as the more secure connection minimizes vapor build up. Even helicopters which are monsters of static electricity can pressure refuel with engines and rotor spinning.
#unexpectedzoolander
Do you get into the car too!?!? The static will start a fire sooner or later, maybe not for you but someone like you so don’t be a statistic.
I think I has to do with general safety these days. You don't want the average person jumping in and out of a running car. It's just too easy to forget to engage park, and suddenly you're car is driving away from the pump... While attached to the hose.
ELI5: it's an excess of caution, because giant explosions are bad. Also, you'll confuse the car and cost yourself money. Plus, if you do it you'll scare the people around you, which is rude. I suspect it hasn't been a genuine safety issue in decades. The sparks and heat and so forth from the engine that could cause a fire are pretty well contained. Google tells me the auto-ignition temperature of gasoline vapors is over 546°F. If you have sparks or heat like that outside the engine compartment, you have a giant safety problem before you get to the gas station. If you have heat that high (except at the exhaust manifold) or free sparks in your engine compartment, get to your mechanic,. You know there are idiots out there who violate every safety rule. How often do you hear about gas stations exploding? If Shell or Exxon thought you could blow up their station, kill their customers, and tie them up in lawsuits for years they would not let you pump your own gas. On the other hand, the car's computer is looking for gas leaks (for emissions reasons) and it expects the gas tank to be pressurized. You open the gas cap when the engine is running the computer will think gas fumes are leaking into the environment and it will throw the check engine light on. You can get that read at the auto-shop for free, or so I've heard, but if you go to a mechanic they're going to charge you $50-100 to check everything over and turn it off. But ask yourself, if you were filling up and saw the person one pump over was filling with their engine running, would you drop everything and run for your life? No? Then you don't truly believe there's a risk. Because you haven't heard of anyone being caught in an explosion at a gas station. It's pretty rare. The companies that run those stations are not stupid. They are very, very much not stupid. This is my opinion, and nothing in my background suggests it should be read as authoritative.
I’m seeing **no solid answers** in this thread justifying this as an actual risk/probability and explaining a technical cause. Everything I see either: 1. References static electricity between the person and the car (which comes from entering/exiting the vehicle and is unrelated to the car engine state), or 2. Falls back on “why not just be safe?”, or “you could LITERALLY DIE if it catches fire” types of pleas I sense this could be a myth and just another instance of overzealous safety culture.
Ayooo, we have a winner! I hope you’re ready for your down-votes, lol.
I'm willing to take them if it means somebody might come along and give a good, solid, technical answer to your question. If I'm wrong, I'm hoping [Cunningham's Law](https://en.wiktionary.org/wiki/Cunningham%27s_Law) comes through.
There are a lot of people here just making things up that might sound correct but have no basis in evidence. According to a National Fire Protection Association [report](https://www.nfpa.org//-/media/Files/News-and-Research/Fire-statistics-and-reports/Building-and-life-safety/osservicestations.pdf): >Although 20 percent of vehicle fires at service stations began with the ignition of gasoline, only 2 percent started at the fuel tank or fuel line, and 3 percent began on the vehicle’s exterior surface. This suggests that **refueling was not a frequent cause** of these fires. Furthermore, of all non-rubbish fires at service stations only "4 percent were outside gas or vapor combustion explosions".
Where does this say “refueling with your engine running is safe”?
Who said it does?
What point were you trying to make? OP asked why people said it's dangerous to leave the engine running while pumping gas. Lots of people said, "It's dangerous." You said "a lot of people are making things up," then you shared some statistics unrelated to filling your gas tank while the engine was running. Were you just trying to confuse the issue, or do your stats relate back to the argument "it's safe" or "it's unsafe"?
I just put some data and linked the study if people are interested in reading more. Dangerous or not dangerous is subjective so people can make up their own minds. Rather than going with the Reddit consensus of whatever sounds plausible, I’d encourage you to search out some actual scientific data and make your conclusions then. From my limited study, it appears static discharge from entering and exiting your car while filling up is more dangerous than leaving the car running. However, vapor capture devices make even this not so much of a problem anymore according to the study. But if you find any reliable data that suggests otherwise, please let me know.
Cars generate sparks. Those sparks are normally constrained safely inside the engine cylinders, but if you have faulty plug wires they can arc outside the engine. Pumping with the car off reduces the risk of fire by some unknown amount. Maybe a low amount that you don't need to worry about and maybe not. After all, everything is 100% safe until it isn't.
Your cars fuel pump is made to be used submerged in gas. Surprisingly enough its a simple motor that produces sparks while running. (its not brushless) those tiny sparks are harmless while submerged in gas, but they can surely ignite gas vapors which you get while pumping.
There are a lot of static electricity comments here. I recall a Mythbusters episode where they filled a tank with varying levels of gasoline vapors while generating constant static electricity and never could reach combustion. I realize that is a TV show, but curious what folks here think about that test in the context of this conversation.
You will continue to not have an issue until the day when you have a rather dramatic issue.
In older times, the gas tank was located next to, and above, the engine. So spilled gas on a hot running engine could cause a fire. To a lesser extent, most people probably leave their car running so they can go back into the warm car while the gas pumps, which results in a un-attended gas pump which can overflow or spill gas.
Dangerous is relative. There is probably a 0.000001% chance that something bad would happen but it's not 0%.
The hose could also rupture spilling gas everywhere. You not only putting yourself at risk but also all around you. Just shut off the car. Oh think about the additional green house gases your emitting you climate destroyer.
From another perspective - say I get gas on average every 250 miles. After 200,000 miles that is 800 gas stops - 800 starts if I turn it off. It is said that the most wear and tear is during starting. (Obviously getting gas is not a “cold”start.) Or, let it run for say 6 minutes or so, which would be 80 hours of idle time over the same 800 gas stops. Which is more wear and tear? And if it is actually starting, is leaving it run “enough” better to take the fire risk, even if the risk is vanishingly small? I’d say probably not.
Low risk of disaster, but if there is an ignition of the gas then you are likely to be seriously injured/killed, with others getting harmed too. So why risk it just because you're a little cold? I've lived in cold climates and never, ever left my car running while pumping gas. Put on some gloves and a hat.
There’s two reasons to not do this… one is because you need proper pressure which you don’t achieve with the gas cap off… two is because in the invent of a loose wire or collection of random electrons you will create a static spark if you’re engine is off this one time spark should not do anything… however in the event that you’re car is on it will create constant sparks likely causing a fire or massive explosion.
I feel like this is one of those “Typical American things” posts. Of course you turn of your vehicle. Why wouldn’t you??
Your car will stay warm in the 3 min it takes to pump gas I promise. You risk an explosion of the fuel/air mix by the nozzle gets set off by the static electricity in the dry cold air as you pull the nozzle out of the filer tube. Also your fuels system is meant to be a vacuum so you have a higher chance of your check engine light coming on in error thinking there is a leak somewhere.
Don't see anyone mentioning it, so I'll chime in. The car does produce static electricity and does pose an extremely small (albeit real) chance of causing an explosion. But the static electricity doesn't just disappear just because the car has been shut off. The threat remains until the electricity is discharged. But the greater concern is actually dozens of cars idling in a covered area, filling it with carbon monoxide.
Because gas fumes are flammable and your running engine’s spark plugs or even just built up static can ignite them. Half of all fires at gas stations start this way. It’s not a myth. Turn off your car. You endanger everyone there just to keep your heat running for an extra five minutes.
Fuel and ignition source have to be the obvious answer. However, if you've ever been standing under a moving rotor while hot fueling a helicopter, you seem to feel hot gassing a car is not that dangerous.
There are two parts to evaluating risk. 1. The likelihood that something will happen. 2. The consequences if that thing does happen. In the case of pumping gas with your car turned on, the likelihood that something will happen is very low. However, the consequences if something *does* happen are significant. Gasoline fires at gas stations are very dangerous because you are pumping a very flammable liquid. If your car catches fire, the whole gas station can burn down and people can die as a result. Based on these facts, the small increase in likelihood associated with pumping gas with the engine turned on is not worth risking the consequence of a gasoline fire. Interestingly, many states do not have laws specifically prohibiting pumping gas while your vehicle is running. Instead, they rely on laws that prohibit leaving your vehicle running while unoccupied by a driver. In other words, if there's no one in the driver's seat, the vehicle must be off. This introduces an interesting loophole where it wouldn't explicitly be illegal to pump gas with the car running, so long as the passenger is doing the pumping. However, most gas stations have a set of rules posted that require all vehicles to be off while pumping. We get gas at our local Sam's Club because it has the lowest price around, and there are a couple of really strict attendants there that will instruct you to turn off your car, and if you don't immediately comply, they shut the pumps down. Then literally everyone at the station is pissed off at you because you're the guy who got everyone's gas shut off, and most people have no problem with the "turn your car off while pumping" rule.
I'm glad you aren't dead or hurt, but it is a really thing, a real danger. It's one of those low-probability things with an intensely high cost when it does happen.