My wife always insists that I turn the engine off while pumping gas. I’ve never heard of an incident where a car blew up or caught fire just because the engine was on. Now we have a 7-month old baby and I figured it’s time to find out the straight dope on this. So, has a fire or explosion ever occurred because of an engine being left on? Also, is there any potential whatsoever of this happening?
Yes, you should turn the engine off. Why? I don’t know. Just do it.
Source: http://www.pei.org/faq/index.asp?cate=4
There are other web sites indicating you reduce the chances for child abduction by turning off the engine and removing the keys while refueling.
Ask yourself one question - Why do I leave the engine running while refueling? Now ask yourself a second question - What safety areas are compromised by running the engine while refueling?
Well, in Minnesota, at least, I believe that it’s a state law and there is a sign asking you to do so at most gas stations I’ve been to. So, if you are in MN, the answer is “yes”.
I always thought that the starter motor would be the easiest way to ignite fuel vapor. My thoughts were that re-starting the car after fueling would be the most dangerous because of this.
I never considered the fuel pump problem before.
New York also makes it illegal to pump gas with the engine running.
Besides, why do it? You do have a self-starter, don’t you, or do you crank the engine by hand? How hard is it to restart the engine when you’re done?
The other problem with leaving the engine running is that a lot of newer cars, in order to run properly, require the fuel system to be sealed. Running the engine with the gas cap off is a “bad thing.” Not sure what the effects might be, but if I don’t give my gas cap at least three “clicks” while closing it, the “check engine” light comes on. Can’t be good.
Another problem with some cars, based on the placement of the tailpipe relative to the filler cap, is that while you’re standing at the pump putting gas in your car, you are exposed to a significant amount of carbon monoxide.
I’m also wondering why you’d leave the engine running while pumping gas, and therefore why it’s even an issue. As far as I can tell it’s a complete waste of gas to idle for 5-10 minutes while you’re pumping/waiting in line/paying/washing windows/buying jerky. Are you a racecar pit crewman?.. maybe you’re looking to make a quick get away after robbing the cashier… or maybe it’s perpetually -150F where you live… 
FWIW it’s illegal in these parts to do it as well. Every gas station has “turn off ignition” signs posted all over the place. There’s probably a reason… then again AFAIK the no cell phone thing while pumping gas is a crock. But like I said above, it makes more sense to turn it off and not waste that gas… and the potential safety factor is a bonus.
Reminds me of when I worked out in rural Saskatchewan; the farmers would pull up in their gigantic pick-ups during the middle of the summer, put 'em in park, and BS for about 20 minutes before going off to whatever they were up to; all the time leaving the trucks running. Never did find out why they did this.
I’ve often wondered the same thing that the OP has. The desire to leave the car running for me is that I have three small children and 1) If they are sleeping the act of starting and stopping the car will sometimes wake them up and 2) In the dead of winter I like to keep the heater going for them.
With regards to Early Out’s comments - I think having the fuel-filler cap on is just an emissions control issue. When you’re fueling the cap is off anyway.
With regards to the hot exhaust components, the tailpipe and muffler are usually on the opposite side of the fuel filler door. I’m wondering the same thing as the OP - are there any documented cases of a fire or explosion caused by fueling up while the engine is running, or is it similar to the “don’t use a cell phone while refueling or in an airplane” where somebody just thinks it’s dangerous?
Although well-meaning, answers of “just do it” aren’t answering the OP.
**mmmiiikkkeee ** said almost exactly what I was going to say.
Myself, having worked around flammable hydrocarbons for 33 years can’t think of NOT shutting off the engine.
Why would anyone want to take a chance?
Personally, I think it’s pretty inconsiderate to leave the car running. There are people who have to work there, and leaving the engine spewing exhaust times X customers per day is pretty miserable. Aside from all of the risks, there’s the simple fact (as mentioned above) that it’s stupid (and often illegal) to leave an engine idling for that long. No car is going to cool dangerously during the five minutes that it’s going to take to fill the car, unless you live in the high Arctic.
As a followup to my OP, I’d like to add that I live in NJ where we don’t pump our own gas. One benefit of leaving the car on is: I can leave the heat or AC on and not have anyone passengers feel uncomfortable.
Also, besides my wife (who is from Canada), I don’t know anyone that shuts their engine off.
Finally, while it is a law to turn the car off, I’ve never once had a gas station attendent tell me turn off my car. These guys work at the gas station so if they felt that there was any danger whatsoever, I’m sure that in my 17 years of driving, at least 1 would’ve asked me to turn off the car.
This is why I’m skeptical and, as aaelghat said, some concrete evidence would be nice.
DeVena, that’s the same quotation that Duckster posted.
Jackknifed, I’m confused. Do you really believe that there’s no common sense reason to turn off an internal combustion engine, that’s generating sparks/heat, etc as a reasonable safety precaution while pumping volitile fuel into your tank?
I’m from NJ as well, and I would turn the car off while it’s being refueled for two reasons: 1. I don’t want to waste gas and 2. I’m trying to be considerate of the person doing the gas-pumping.
If the windows are closed it does not get all that cold in the short time it takes. Obviously a separate issue in those places where you have to keep the engine heated overnight in order to be able to start it at all in the morning.
My first thought was about the kids putting the car in gear while you were pumping gas, the stories of 2 year olds wrecking cars are pretty common.
Unclviny
On my car the gas cap is opened with the ignition key, so you have to turn the engine off before refuelling (unless you were to carry around a spare key specifically for the purpose of removing the gas cap). In this way I suppose the manufacturer “enforces” this behaviour, unless the key is required to prevent someone siphoning petrol out of your tank.
Cerowyn,
I know your question was directed at Jackknifed, but think of it this way… There used to be signs on fuel pumps saying that cell phones can cause explosions if used while fueling up. Someone could have legitimately asked, “Do you really believe that there’s no common sense reason to turn off a cell phone while pumping volatile gas into your fuel pump?”. Common sense would say there’s a risk, but Snopes showed there was no empirical evidence to support that claim.
The same question is being asked here. The OP’s question was “has a fire or explosion ever occurred because of an engine being left on? Also, is there any potential whatsoever of this happening?”. Because I was curious like the OP I’ve been searching for evidence of any study that has shown that having the engine running has caused an explosion while fueling. There have been loads of cases that talked about static electricity causing explosions, but that is unrelated to the engine being on or off (and in that case the spark is millimeters from the fumes).
To me, when you refuel with the car running, several factors reduce the risk to effectively, zero. 1) Several feet separate the fuel nozzle from anything that is hot or causes a spark, 2) Fuel vapor dissipates quickly, yet needs to be concentrated to foster an explosion 3) Millions of people (I’m guessing) refuel with the engine on on a daily basis and 4) Nobody has been able to point to a study or documented case that shows this is an actual risk.
There maybe other reasons to turn the engine off (save gas, reduce carbon monoxide, etc.). But the OP’s question was about the risk.
There was an incident not too long ago about a gas pump exploding near a running car. Don’t remember where I saw it - could have been a story on one of those daytime talk shows (Oprah? Montel?). It can happen, although it is highly unlikely. Certain conditions make it more likely. A close to empty gasoline storage tank can accumulate gasses that are more likely to ignite and produce an explosion. So, instead of gambling on how full your local gas station’s tanks are, turn your car off.