I was told that I could do this on some of the older MBs. What are the qualifications that need to be met for this to be safe?

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1988 Mercedes-Benz 260E (W124)
Arctic White/Grey
Debadged
Euro Headlights
Clear Turn Signals and 1994/1995 Taillights
16" x 7J 8-hole
Michelin Pilot HX MXM 205/55WR16

1997 Mercedes-Benz E420 (W210)
Pearl Black/Ash
Debadged
Michelin Pilot XGT Z4 P225/55ZR16

1997 Mercedes-Benz C280 (W202)
Polar White/Parchment
Michelin Pilot SX-GT 205/60VR15

It's not really safe to do, *but* I won't say I've never done it. For example, when my car had a dead battery on the way to Florida I refueled the car (twice?) with the engine running.

Just make sure that you don't get a spark across the filler neck and the nozzle. It's a good idea to ground yourself to the car and the nozzle first. I can say that I can count the number of times that I have done it on one hand.

When I do it, I always make sure I'm smoking a cigarette at the same time, it helps me relax. :)

Unless you have a Mercedes with Diplomatic plates you can't do it with any model. Why, because its against the law. If that doesn't bother you, the only models I can't see any harm really with any model. People used to do it all the time, then somebody had to go and blow up a gas station by pumping gas with his engine running (probably smoking man :)) and that was the end of it. I can't see much risk of explosion if you're filling up with diesel.

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Jason Priest
1986 420SEL

The qualifications I recommend are your basic racing pit crew safety gear. Helmet, full Nomex suit and a safety man with extinguisher handy. Man, that would be a sight at the local Gas 'n Go! :D

Seriously, I cannot recommend leaving the engine running. Yes, I've done it too. :o

First, sparks, spills, etc. could incinerate you, your car, and the station. 6 o'clock news stuff, that! :(

Second, I heard of cases where someone pulled up, filled up, and left the keys in the ignition. As they went to the window to pay, a low-life slid into the car, now full of fuel, started it and drove off! :eek: With the motor running, it's even easier.

If you have a hard time re-starting it, get it fixed, don't leave it running.

BCingU, Jim

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'96 E300D 60k mi (wife's daily ride)
'95 Audi 90 120k mi
'92 GMC Suburban 139k mi
'85 300SD 234k mi (my daily ride)

My Carhartt jacket has a tag that reads (I'm not making this up) "Do not use this garment where there is a danger of clothing ignition." Should I take it off while refueling with engine running and smoking cigar? Another safety tip (from early Japan car owners' manual): "Go gently through the greasy roads for there lurks the skid demon."

I don't think it's safe but it's not all that dangerous. Gasoline fumes at atmospheric are far too rich to be explosive. You could smoke a cigarette and fuel your car and nothing will happen, 99.999% of the time that is.

Yes. Gasoline fumes are either too lean or too rich to ignite "most" of the time. I've seen people put out cigarettes in a capful of gasoline.

I shook my head in disbelief when the warning about using cell phones while refueling came out. I'd think that the risk of staticky shoes creating a spark while removing the filler cap would far outweigh a cell phone igniting anything.

But, in our litigious USA, anything that could happen has to have a warning label...

Up until a couple of years ago, I rarely if ever turned off any vehicle I was re-fueling. The above post regarding mixture/fuel richness in this atmosphere etc is one reason. The other is that fuel vapors (the dangerous part) will in many cases be swept under/into vehicles and also into the engine area. If the vehicle is running, the sources for ignition are alternator, 12v ground circuit (battery, very low current flow when engine running, unless battery is discharged) and lights (maybe, and very low chance for arcing) and the ingition system (plug wires, rotor (or electronic). Not to mention the fact that there may be a viscous fan (or electric) running to blow away any fumes before they even reach a source of ignition.

Now lets look at a vehicle that is shut off. If there are any fuel vspors that are around, and may have had a chance to get to a dangerous place (engine bay) when you go to crank over the engine we have the starter motor (big current. lots of arcing), the metal teeth on the starter gear engaging the flywheel (could be a spark), the ground circuit (battery, big current flow), alternator (now full fielding to recharge battery), lights coming on (better chance for an arc than if they were already on)

I explained this to several "gasoline technicians" who would not fill my car while it was running, and I was rewarded with puzzled stares. Some would fill it, some wouldn't. With my MB I only go to self serve anyway, so usually not an issue.

I think the reason for turning off the vehicle is that there are a small percentage of drivers that are just plain idiots. I have watched people drive away from the pumps with the hose still in the tank (those hoses can REALLY stretch) Whether turning off the car would have prevented this, I do not know. Another reason could be for the safety of the attendants (safety from these same sort of drivers "accidentally" popping a car into gear and running someone over)

If I leave my car unatended and runnning, the doors are locked and if the vehicle has an alarm or brake switch kill, it is activated, even if I am only a few feet away. It only takes a second.

All of this is just my speculation, and of course everyone is free to have their opinion. For me, the less my car has to be turned on and off, the better. Cars tend to last longer that way.

Great thread!

Trent,

Nice try, I ain't buyin' it.


On the serious side, if you were in a situation where your car won't restart, and your going cross country, this is sort of an emergency situation in which you can't in practicality repair it, carefully refill with engine running.

If you're just leaving the engine running to keep the inside warm on a winter day, come on, why take such a risk. Also someone pointed out the possibility of getting it stolen while paying. About 20 years ago, my Dad got his brand spanking new pick up with lots of tools and expensive stuff inside, stolen almost the same way. He was standing inside the service station office ten feet from the truck telling them he was leaving a tire to be fixed. As he walked out the door, someone drove it away with him yelling obscenities at them. He hasn't seen it since.

Is keeping the inside comfortable worth taking such a chance? With a diesel, I think the chance is almost non-existent. Given the volatility of gasoline, on the other hand, I'm not doing it. I'm a country boy, and as a kid started trash fires with gasoline. Maybe under CERTAIN conditions you could put out a cigarette in gasoline, but I'm not trying that or anything else while standing over 18 or 20 gallons of the stuff.

If you've never started a fire with gasoline, I wouldn't recommend trying it, just to find out how quick the stuff goes up. Take someone's word for it.

But if your suicidal tendencies are stronger than your survival tendencies, I say Go For It.

Best of luck to everyone on this,



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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, manual, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

WOW, I've been living on the edge for years! On cold winter days or hot summer ones for that matter I rarely shut the car off to re-fuel. From what I have seen 75% of folks around here live as dangerously as me, seems like all of the cars at the pumps are running anymore. I have to go along with Trent here, his approach is logical, a modern running automobile has few if any ignition sources. I also would be more concerned about fumes collecting under the hood of a non running car being ignited by a starter motor or alternator recharging the battery after a start up. I view it as big brother reaching out to help those lacking good judgement skills. And typical of government mandates it is based more on fear than fact.

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90 M-B 300GE 5sp
98 BMW 750iL
86 Porsche 944 Turbo

Folks,

I view the law as big brother also. I just don't want to practice this myself. We all take responsibility for our own actions. I've seen what a quart of gasoline can do, I personally elect not to take a chance on seeing what 18 or 20 gallons of the stuff can do. How much trouble is it to twist the key to restart the engine after a few minutes?

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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, manual, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

I'm not advocating risking your life to fuel your car. What exactly is the scientific basis for shutting the car off? I see quite a bit of merit in Trents post even if some of it was tongue in cheek. With splash gaurds, auto shut-offs the pumps are pretty safe. There is not even a possible source of ignition at the rear of my car, running or not. If there is a logical scientific reason, show me. I didn't intend big brother as a scapegoat for doing something foolish. It is undeniable though that many of these rules are based soley on fear or a reation, instead of fact. I do not recall hearing about a vehicle exploding at the pumps in the last 15 years. Is it really a concern?

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90 M-B 300GE 5sp
98 BMW 750iL
86 Porsche 944 Turbo

There is just as much risk from igniting fuel when filling a car off as there is when its on. Either way anything hot comes into contact with that fuel you're blowing up, period! In an automatic only USA I think the engine should be turned of to avoid accidently engagement of the transmission (kids or a pet) and freaky stuff like this.

I'm afraid there is no getting around the NO SMOKING sign however :D

But, the gastank filler makes such a convenient ash tray.

Larry