Running engine while pumping gas

[Triumph]

I'm having this discussion with a friend on Facebook. Please try to think of a situation or scenario where running your engine while pumping gas, will cause a fire. The car running must provide the source of ignition, anything can happen to the car, or to the pump, or the owner can be a dumbass somehow, but your proposed scenario can only happen because the car was running. After creating the scenario, ask yourself, "Could this have happened with the car off"?

I'm coming up pretty empty handed.

 

[LTC8K6]

Alternator is the one that always comes up.

 

[PsiStar]

Why the f does anyone get out of the car & leave the car running?????????????? Unless the battery is complete crap & might not restart the car.

Dumbest f'n thing I have ever seen ... and too often. I have only witnessed this outside gas stations. The dumb-asses either pull up to the front door just to run in & by cigs (maybe there is a stupid is as stupid does trend here) or they pull up to the pumps, leave the car running ... and THEN run into the station. To what? Pre pay??????

 

[Triumph]

Alternator is the one that always comes up.

Please explain. Saying, "the alternator" is not enough.

 

[skyking]

All the electrical systems are running. The exhaust is hot. Spark and combustion. Odds are higher that a car will catch fire while running.
I've seen a couple burn down when parked but not nearly as many as the ones that were running.
Add in a high volume fuel source and it is easy to see why they want the engine off.
Another thing to think about: Many laws and rules that seem stupid now can be traced back to some horrific accident in the past.
The occupancy rules and fire exit rules came about after hundreds died in several fires, for example.

 

[Bignate603]

Could there be an ignition source? Yes. You've got something burning gas, exhaust that could backfire and full of electrical contacts that could spark.

Is it likely? Probably not. Most of ignition sources are pretty far away from where you fill the gas and the chance that one occurs when you've got enough gas fumes around it to ignite. You're more likely to ignite something due to static discharge if you take your hand off the pump while you're pumping.

I'm with Psistar though, why would you ever leave your car running when you're pumping gas?

 

[Triumph]

All the electrical systems are running. The exhaust is hot. Spark and combustion. Odds are higher that a car will catch fire while running.
I've seen a couple burn down when parked but not nearly as many as the ones that were running.
Add in a high volume fuel source and it is easy to see why they want the engine off.

Please extrapolate: imagine a scenario involving the electrical system and how it would start a fire while pumping gas.

You're more likely to ignite something due to static discharge if you take your hand off the pump while you're pumping.

Which happens regardless of the status of the ignition.

I'm with Psistar though, why would you ever leave your car running when you're pumping gas?

I turn my ignition off. But my interest is one of principle. I don't believe in doing something "just because," you have to provide a valid reason.

 

[SparkyJJO]

Even if you just forget about safety for a moment, there is still no reason to leave the engine running while pumping gas. It's just wasting gas sitting there idling. Oh, and leaving you to breathe exhaust fumes while you stand near the rear of the vehicle pumping the gas.

 

[IcePickFreak]

Could there be an ignition source? Yes. You've got something burning gas, exhaust that could backfire and full of electrical contacts that could spark.

Is it likely? Probably not. Most of ignition sources are pretty far away from where you fill the gas and the chance that one occurs when you've got enough gas fumes around it to ignite. You're more likely to ignite something due to static discharge if you take your hand off the pump while you're pumping.

I'm with Psistar though, why would you ever leave your car running when you're pumping gas?

Up in the northern states when it's sub-zero temps people will run out and put the nozzle in and then run back inside their car to get out of the wind & cold. Oddly enough I use to see it a lot more often 15-20 years ago, not sure why the change, but now most people usually seem to stay outside with the car off. Guess those signs on the pump worked.

 

[BoT]

you are more at risk with a cellphone then you are with a running engine.
i used to leave my engine running all the time and sometimes i still do. it's more of a habit then a conscious decision. i used to be a delivery driver and a mechanic told me that it is actually not good to turn off the engine for short periods of time plus you use as much gas starting the engine back up then you would leaving it running.
i have no idea how valid these claims are but back then i didn't give it much thought.

there should be no way that your catches fire if your engine is running while you pump gas. even if you spill a few drops when you pull out and for some odd reason those drops would ignite, it would not set your car on fire unless your gas tank is leaking and then you are in danger anyway regardless if the engine is running or not. in fact, even if your gas tank is leaking it is unlikely that the car suddenly combust. vast majority of gas tanks have a vacuum inside and fuel still needs oxygen to burn.

 

[thescreensavers]

People in other contries run there car. I turn mine off w/e

Using a Cell phone in what way? Calling? I Just use it to tally down my mileage and gallons

 

[jlee]

I typically leave the cruiser running - fill up is quick...usually 4-6 gallons. It's also damn cold in the winter. It hasn't exploded on me yet.

 

[Zenmervolt]

i used to be a delivery driver and a mechanic told me that it is actually not good to turn off the engine for short periods of time plus you use as much gas starting the engine back up then you would leaving it running.

If you're a delivery driver and making many stops each day, it's hard on the battery to turn off the engine every time (you generally need to drive the car for 15-20 minutes to replenish the battery after a start). The battery has enough reserve capacity that the occasional short trip is fine, but if you have 20 or more starts each day like a delivery driver would if they shut the engine off every time you'll end up wearing out the battery much faster.

You'd need to leave the engine off for quite some time (perhaps an hour or so) for the oil to drain out of the top end enough to cause any meaningful startup wear, and you'd need to wait longer still for the oil to fully cool and really get back to a state where startup wear is a concern.

The fuel usage argument used to be true with carburetors, but modern EFI is incredibly good and you'll generally use less gas by turning the engine off any time you'll be idling for more than a few seconds (this is why the engine stop function for hybrids yields useful increases in fuel economy).

Back to the OP, the biggest concern I can see about a running car while pumping gas is the car somehow getting into gear and moving without anyone in it. Granted, this would be incredibly rare, but it's still something that could really only happen with the car running (or, at least, it would be exacerbated by the car running).

A less immediately-dangerous issue might be the potential for an opportunist to jump into your car and drive off with it as you're pumping gas. Yes, they could mug you for your keys even if the engine is off, but with the keys in and the engine running it's much easier and less risky for them.

ZV

 

[Bignate603]

Up in the northern states when it's sub-zero temps people will run out and put the nozzle in and then run back inside their car to get out of the wind & cold. Oddly enough I use to see it a lot more often 15-20 years ago, not sure why the change, but now most people usually seem to stay outside with the car off. Guess those signs on the pump worked.

I grew up in upstate NY and the norm was to stand there pumping the gas. I did see people leaving their cars running though while they ran in to stores relatively often. People with diesel pickups seemed to do it the most often which seems more understandable. Block heaters weren't unheard of on diesels but were less common than some other parts of the country.

 

[herm0016]

if its cold i will leave my truck running sometimes, keep the heat going, i get back in if it is a long fill, usually only when very windy or below zero.

if i am in my work truck ( f-350 diesel) I leave it running all the time in the winter, shut if off sometimes during the summer.

 

[LTC8K6]

Please explain. Saying, "the alternator" is not enough.

Gasoline fumes from a spill and the ignition from the brushes in the alternator is the usual scenario on the web.

 

[Mike Gayner]

Pumping fuel increases the risk of a spill, which increases the risk of a high volume of fumes getting sucked into the intake, which increases the risk of the engine over-speeding and causing a source of ignition (exactly what happened on the Deep Horizon platform).

 

[dawp]

Even if you just forget about safety for a moment, there is still no reason to leave the engine running while pumping gas. It's just wasting gas sitting there idling. Oh, and leaving you to breathe exhaust fumes while you stand near the rear of the vehicle pumping the gas.

the tail pipe is usually on the opposite side of the car from the the fill port. And if the wind is blowing, you'd have to be huffing exhaust right out of the pipe to breath much of it.

 

[skull]

When I was filling my new beater up last week it started pouring gas from the tank as it got full. I had a lot of gas on the ground probably about half a gallon. I'm glad I left it off who knows what would of happened. When I left one of the workers helped me push it so i wasn't starting it up right over the giant puddle. I did manage to drive it for 50 miles leaving a trail getting the excess out without the brakes catching it though.

I used to always leave my cars running. Until my mechanic buddy told me you can cause vapor lock of the fuel pump. All the air bubbles getting pushed down with the gas can get trapped in the pump.

 

[Triumph]

Gasoline fumes from a spill and the ignition from the brushes in the alternator is the usual scenario on the web.

Thanks for a somewhat plausible scenario, but I guess the spill would have to be quite large for the fumes to get all the way to the front of the car, where the fumes would have to be intense enough that they are not simply blown away and/or diluted by the open air, and then still be of sufficient air/fuel ratio to actually ignite. (the fumes would likely stay on the ground since gas fumes are heavier than air)

Pumping fuel increases the risk of a spill, which increases the risk of a high volume of fumes getting sucked into the intake, which increases the risk of the engine over-speeding and causing a source of ignition (exactly what happened on the Deep Horizon platform).

The first reasonable explanation I've seen based on something factual, but can we agree that the Deepwater explosion was a massive bubble of highly explosive methane, and pumping gas is nowhere near as dangerous an activity as deep water off shore oil drilling.

 

[sdifox]

Up in the northern states when it's sub-zero temps people will run out and put the nozzle in and then run back inside their car to get out of the wind & cold. Oddly enough I use to see it a lot more often 15-20 years ago, not sure why the change, but now most people usually seem to stay outside with the car off. Guess those signs on the pump worked.

because the mechanism to keep the gas flowing has been deemed unsafe so pumps don't have those locks anymore.
you could trigger a CEL if you open the gas cap while the car is running.

 

[jlee]

because the mechanism to keep the gas flowing has been deemed unsafe so pumps don't have those locks anymore.
you could trigger a CEL if you open the gas cap while the car is running.

They do up here. I try to avoid gas stations that don't have them.

 

[HarryLui]

Getting yourself in and out of the car is worst, it'll create static.

http://www.youtube.com/watch?v=7KK48hQ78Kk

 

[sdifox]

Gasoline fumes from a spill and the ignition from the brushes in the alternator is the usual scenario on the web.

Pretty sure the alternator is far from the refueling port.

 

[sdifox]

They do up here. I try to avoid gas stations that don't have them.

We don't have those anymore. So we stand outside or pay for full service.

And because they don't want excessive VOC, the flow rate of the pumps have been lowered too...

double whammy.