No, I’m not. Moving cars are hotter internally, and the fuel pumps are arranged such that if the wind is blowing the right way the vapour could easily blow from the car you are refueling to the adjacent lane that has a running car that just arrived.
Still not the same thing as a gasoline spill under a running car.
So, it’s dangerous to spill gasoline under a running car which has been stationary for the past 30 seconds, but it’s perfectly safe to spill gasoline under a moving car which just pulled into the gas station and is maneuvering between the pumps? I don’t buy it.
If we had a law which said “No fuel may be dispensed in the presence of any vehicles whose engines are running.”, then I might believe that there was something to it. If the rule were that you pull into the station, shut off your engine, and also no other cars are allowed to enter or leave the station while yours is being fueled, then that would make sense. But to suggest that your running car is dangerous and ignore all the running cars around you who are coming in and going out… that’s just silly.
So far, I’ve heard two logical explanations for requiring you to shut off your engine: #1 comfort of the people around you, and #2 preventing the vehicle from accidentally being put into gear while the driver is outside the vehicle. A possible third reason is to avoid wasting fuel, but that doesn’t explain why it would be a law. There are plenty of legal ways for you to waste fuel (if that’s what makes you happy).
This is the “vaccination” problem.
The likelihood of a refueling fire is very slim these days - it was probably worse in the past (although still rare). But, refueling is an activity that happens many millions of times every day, so even if the probability of a fire occurring to a particular individual is vanishingly small, it still makes sense to lower those odds even further by adding refueling restrictions.
I think the correct answer can be found in post #69
Take a Model A Ford as an example. The gas tank was between the dashboard and the firewall with the gas cap in front of the middle of the windshield.
The ignition system was… Primitive would be the word. The spark plug “wires” actually weren’t wire but pieces of flat metal strapping that clipped on the distributor and the spark plug. The straps were uninsulated at both ends.
If you left this engine running and had a spill at the filler neck there is an excellent chance the gas would wind up in the engine room causing the spark to flash to ground igniting the fumes.
There is no way in hell I would fuel a running Model A. A modern car? No such worries.
This is 99% correct. 
I believe Mercedes also runs a pressure check; I’m not sure if there are more. Of course if the pressure check occurs while refueling with the engine running, my scenario (more vapor being released) could come into play. Now I come to learn that ordinarily the fuel system is likely to be at a slight vacuum when a car is running. So while this would actually reduce the release of fuel vapor while refueling, it is offset by tailpipe emissions and fuel burned. I don’t know which is worse.
I surprised that no one has mentioned the increased chance of having one’s car stolen if left running.
I agree with those who are explaining why there is close to zero additional risk of fire by leaving a car running when filling up. This wasn’t something to worry about even back when cars were not nearly of the quality as they are today.
Yes, engine running, blades spinning.
The swash plate itself does not spin on the outside where the flight control links hook up, It is just a big round bearing more or less.
It was about a foot below the blades.
The blades were not the dangerous part, it is the spinning inner ring which has controls hooked on it to transfer the changes to the spinning blades. Your hands would be inches from them controlling the end of the grease gun. All the while hanging on the side of the running helicopter.
I always was supper careful with my wipe rags because they could really easy get caught and then their would be hell to pay.
Same for the fast spinning tail rotor shaft bearings, getting wrapped on that would spoil everyone’s day.
Not saying it was smart, allowed normally, just that on many small helios we did that.
It was all about keeping the birds in the air in the best condition we could.
Remember, this was long ago & far away. 
Myself and those around me never had an accident. 
Not many people were stupid enough to even try to do that. :rolleyes:
Kinda like I am about wing suit flying. Glad that did not become popular until I was old nuff to realize I was not a good candidate for that activity. :eek:
Just a little nitpick, the Huey(I don’t know what you were on) has a rotating swashplate and an nonrotating swashplate. The control flight control rods went to the nonrotating swashplate which transfered the position to the rotating swashplate and its control rods to the blades.
Yes my crew chiefs worked on the Huey while running also. That was okay but some didn’t wear hearing protection.
I know from owning a Volkswagen that a leak in the fuel system could lead to an engine code being thrown. At least one dealer I had been to routinely advised their customers to be sure the gas cap was on tight so that their check engine light did not come on. It was routinely discussed in online forums for Volkswagen. It was common to have to replace the rubber seal on the gas cap to prevent codes from being thrown. Now, this may only happen during the test phase, as you said, but since the driver has no control over when the test phase will occur, is it not prudent to simply avoid EVER running the engine with the gas cap off?
Yes the system is designed to detect a leak. You leave the gas cap lose, it will set a code and a check engine light. I always advise my customer to make sure the gas cap clicks when the install it to ensure it is tight, yet I still see evap codes as the most common code in the shop.
That is not what I was replying to however. rsa said
Gas tanks on modern cars are NOT pressurized and this is a false statement except for those cars that do pressurize the fuel tank very, very slightly to test for a leak, at one specific point in the drive cycle. Hell there are some cars out there that only test with the engine off, so for those cars this statement is 100% wrong. There are also some cars that suck a slight vacuum in the tank to test for a leak. Again rsa is 100% wrong.
I was not expressing an opinion that refueling with the engine running was a good idea and would not set a check engine light, I was pointing out that rsa’s statement was false.
Don’t forget everyone that the shut off engine signs far predate OBDII cars, I remember them from the 1950’s so this talk that the signs are there to prevent check engine lights, or because of hot converters are straw men.
Yes… I did not know you knew what I was talking about. Never called it two different things, ‘swashplate’ meant the whole thing and since they are pretty much a one piece deal … blah, blah.
I was trying to make my post understandable to a non aviation person. I guess I can put this in my bulging file labeled FAIL … 
So, did they grease the assembly while running?
The Huey was really new back then. I only saw ‘A’ back then.
I did go to school on them and loved to try to make sense of the intermixing bell crank by just visualization when I was really wanted to see if I had gone crazy on any given day. Bawahahaha 
hope it didn’t sound too snarky, didn’t mean it that way. A model. Thanks for making me feel young. I tell kids now that we didn’t have Blackhawks or Apaches when I was in and the don’t believe it. Actually Bragg and Campbell were just getting them.
yes they did a lot while running including grease, AFAIW.
Well, if you want to get technical, I never said you WERE expressing such an opinion, so nyah, nyah, nyah.
I don’t think I said anything about signs, did I?
No but perhaps you noticed the subject of the thread…
Engines used to backfire and scare the pump operator. Its more scary to the person operating the pump on the same vehicle that backfires… its a brain instinct panic thing at work… defied logic… eg the person operating the pump may believe its the fuel causing the problem and spray the fuel around.
(Of course someone elses car may backfire, but thats not so likely to induce panic.)
Also many vehicles have a bad park brake … a driver will more likely leave it in D if the engine is also running. Its the habit of being stopped while driving… eg for the hill start, just pull on the park brake.
Where on earth do they teach drivers to do that on anything but having to stop going up a steep hill? ( Actually it is a method for some specific things beside hills but they do not occur in most peoples driving life. And in a fuel station? )
Who on earth would that be the normal thing to do everyplace? How would it become such a habit that you do it when you are out of the car for any reason? 
I am actually really really asking?
Now that I think of it, the regulations to shut off the engine when fueling were created back in the 1950s, if not well before then. At a time when most or even all vehicles would be manual transmission. And many would be much balkier to start than modern cars are. Heck, the regs might even date from the era of hand-cranked starters although I doubt it.
In the say, 1930s to 1950s era, the choice would be to leave the engine running, manual transmission in neutral and parking brake set, or to shut the engine off, leave the transmission in some gear, and set the parking brake.
I could certainly imagine a lot of people preferring the former as quicker & easier, but the safety folks preferring the latter as smart & safer for all concerned. Couple that with fuel tanks & filler ports near the engine compartment and it makes sense to mandate “engine off to fuel”.
A valid question is whether the regulations have a meaningful safety benefit nowadays. My bet is some, but darn little. Certainly far less benefit than they had back when they were enacted. OTOH, our tolerance for avoidable mishaps is much reduced from the old days too.
And I agree with the poster up-thread that suggested the failures most avoided today by these regs are driving away with the dispenser nozzle still in the car’s filler port.
A few years ago, at one of our company safety meetings, they mentioned the proper procedures to pump gas safely. After the presentation, on co-worker announces to another…
“And remember, Angie, take out the hose and hang it up before driving off.”
Angie replies “Well, that’s why I don’t pump my own gas any more…”
Last year, I pumped gas into my car while next to a tractor-trailer carrying fireworks. (At least, that’s what the sign on the side said. It could’ve been empty.)
Made me a little nervous, but at least both our engines were off.
Yes, I was referring specifically to the Model A (I had a '29 tudor in college). The big worry wasn’t the (copper) strips - properly installed, they were secured by the nut on the spark plug (yes, old spark plugs had threaded posts with a nut on them) and the spring in the metal kept it against the post on the distributor body (which was long enough to have a post for each of the 4 cylinders a the same distance - the copper strips were all the same length). Never had one come loose and spark.
Whew. After all that - the worry was the exhaust manifold and exhaust line which had all of maybe 10-12" from the filler. A splash would find it. Fuel hitting the head would run off - all of it running down the starboard side would find the manifold.
Don’t know when the fuel tank was moved aft - it required the development of a super-reliable fuel pump. The tank-at-top-of-cowl provided a gravity-fed system.