This is one of those things I've always wondered about. I always turn off my car when I fuel up, I guess just because it seems like common sense, and that's what my parents taught me (kind of like saying thank you and not picking my nose in public). Fairly often I see people gassing up with their engine running, and I always have the slight fear that the car is going to blow up or something. It just doesn't seem like something you should do, though I have absolutely no idea why (beyond obvious what-ifs like the car being put accidentally into gear). Can someone knowedgeable chime on here?

I figured this would be a good Friday thread...

 

This is one of those situations kind of like cell phones on airplanes, and insurance: There's a chance that bad things can happen; How much effort are you willing to put into protecting yourself from a possibility?


There is definitely a danger involved in refeuling with the engine running. There is also a slightly lower danger involved when refueling with the engine off. A random spark can ignite the fumes from the filler opening and cause a fireball that could engulf you and the car. I've seen several video recordings of this, and it is super nasty.

Filler hoses are designed to reduce the amount of fumes that escape, but they're not perfect. Sparks from static electricity can ignite the fumes just as easily as sparks from any electrical car component. (Or cell phone - you *have* noticed the signs on the pumps that say to turn off cell phones, right? This is why.) The chance of static causing a spark is of course increased in cold, dry weather.

I always turn off the ignition when refueling, and I try to handle the filler in such a way that any static discharge will occur directly through my hand rather than an air gap near the filler. I figure it's worth that much effort.

Finally, (And I know this has little bearing in your area, being from Massachusetts originally myself) It's illegal to leave the engine running while refueling.

Be safer - turn off the engine - don't slide out of the seat - touch your hand to the car body while holding the filler nozzle, before the nozzle gets near the filler opening on your car.

_Dave_

 

I know that it is OK to fill up with the engine running if you have a DIESEL car because the fuel is not as combustible as regular fuel.

That being said, it must be unsafe to fuel with the engine running if you're in regular fuel line. TOO, it's very unsafe to talk on a cell phone while filling up for gas, as a friend of mine was doing it and got yelled at over the speaker phone by the 'pump lady' inside. Don't know why for that one though....

 

How about turning your car off when fueling because not doing so is illegal in most if not every state in the US? It's not just a safety issue, it's the law...

 

Ech, screw the law. Safety first.

 

True but since the safety part doesn't seem to phase people maybe a fine would?

 

Regarding the cellphone igniting the gas whilst fillling, here's the most recent rebuttal to this "urban legend"

http://news.bbc.co.uk/1/hi/england/kent/4366337.stm

As this article indicates, it's static electricity that is the culprit in the majority of cases.

Another study I've seen says that many of the incidents are with women, who go back into the car to retrieve their purse -- thus building up a static charge (again). The first time out of the car, if they had a static buildup, it discharged against the pump. But the second time getting out and then immediately touching the pump while in the car, this discharged the static charge near the fumes and voila.

In addition, the "Mythbusters" show did an episode on this and couldn't get it to work either.

 

Not matter the source of the static discharge, you still need the right fuel vapor / air mixture at the right moment to have a fire. Just because you can smell the gas does not mean it will catch fire, eh?

 

I guess I'm screwed. I fill up my car when the engine is running, and pick my nose at the same time

Seriously thought, once in a while I do fill up without turning the engine off, it's because I forget to turn it off.

 

I just can't imagine doing that... But maybe it's because 99% of the time when I exit my car I shut it off first no matter where I am...

 

Me neither.

Tell you what, those of you who do leave the car running to gas up, please use a different gas station than the one I use.

 

Eh, not too worried about it When it happened, it was probably a freak accident.

I think it has a lot to do with growing up in a hot weather climate. It's so hot, that you can't afford to turn your car off while refueling, otherwise you melt in your card

 

I remember reading once where a service station attendant called a "hotline" number posted on his station's wall and asked if the stuff inside a fire extingisher would ruin the gas in the underground tanks if it was sprayed in there.

The guy on the other end couldn't help but ask WHY? Turns out the attendant was checking the level with one of those long wooden measuring sticks and didn't have a flash light.................yep, he used his trusty bic lighter, once again proving that gasoline is indeed flammable.

 

What a minute... I thought gasoline was inflammable!

 

And here's why. Newer tire compounds have more silica, and less carbon, so they have higher resistivity. This is worse with dry air, as it will support more static charge (read create a longer spark). How many of you have felt a shock when you get out of a car. This is static discharge. It started becomming much more of an issue in the late 80s and early ninties (some tires on Hondas were so bad the shock was scary!). Performance tires aren't as bad, but the trend will get worse. The notion of deisles idling at filling is just lazieness. While the deisle is more of an oil with a much lower vapor pressure, its is flamable. Deisles used to idle all the time due to warm start and other issues, and the habit dies hard.


Yes the chance of going up in an explosive fire ball is small, but shutting off the car will keep the motions of the belts and the like from creating more friction, and static. It's a wise move that costs nothing.

Matt

 

In California it's illegal to leave a motor running when stopped anywhere other than a motorway (street or highway). No idling allowed in driveways and parking lots. It should be common sense--why try for zero miles per gallon. Maybe some people want to see if they can consume fuel as quickly as they can pump it in. Or perhaps there are too many wonderful distractions in life to worry about such trivialities. As Gloria Swanson said in "Sunset Boulevard", "It just keeps pumping and pumping and pumping..."

 

Hubby says that if you leave the car running, go make a call or deal with something electrical, get back and sit in the car's seat, you might generate static electricity, and when you grab the pump handle again, you could send off a spark, which could ignite a fire!


Clover

 

I am completely alert to as what may cause fires, since I was seriously burned as a toddler, and I will always feel the effects thoughtout my whole life.

Monkey Boy, if you smell fuel vapors, they will ignite. and even if you don't smell them also. I am a burn survivor learned that most times that the fumes float within an 18 inch area from the ground up due to the weight factor, thats if you dropped a can of gasoline on the ground with no wind. highly doubtable, but.. you do need to factor in wind, it will cause the fumes to rise or lead to the tailpipe or underneath the exhaust of your vehicle. . fumes will go wherever the wind takes it. ANY amount of heat with the right mix will cause ignition of the fumes resulting in a chain reaction to the source of the fumes.

So in other words, Turn it off.

 

At my first fill up compliments of our dealer, my husband left the car running (which I never do). The pump kept turning off prematurely. Then I read and I believe this was in the MINI manual, that the fumes generated from the car running will not allow the car to be filled properly. That would explain the pump constantly turning off. Since then I always turn the car off when refueling and there never has been a problem. So, if not for safety or the law, it's just easier to get a full tank without any problems (at least in my experience). :smile:

 

... and if the engine is running and you take the filler cap off, doesn't your "EML" light come on?? mine does ...

 

Up here the attendants won't let you fill up with your car running,period.

 

Ive only done it once on a turbo charged car which couldn't shut down due
to its cooldown cycle. I was expecting the CEL to turn on because the
pressure changes without the gas cap, but it was fine.

I wouldn't do it again though...