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Ouch, I put gas in my Diesel tank, how much is too much

Turbine Doc

Turbine Doc

Just Another Diesel Guy
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Good discussion here, http://www.thetruckstop.us/forum/showthread.php?24508-Oh-h!t....I-put-GAS-in-my-fuel-tank!

but the only sure way to be 100% sure is get out the gas, since we now ultra low sulphur Diesel, do the conventions of old hold true a little gas won't harm us, just how much gas in your modern EFI engine would you deem to be safe to blend with your Diesel, and if it happens accidentaly, what should you do about it ?

We have several memers here that are in the business of making fuel for a living, we particularly would like that input.
 
Subscribing... Not that I have any intention of screwing up mind you...:rolleyes5:
I do believe I would have considered running it with a fill up of the rest diesel since it was only 2 gals. Then change the FF.
 
I've purposely dumped 2 gallons of old gas in my 500 gallon tank.
The guy that runs the fuel truck said he has never had a problem dumping diesel after gas with a full hose.
2 gallons in a 30 gallon tank would make me nervous. I'd probably dump in at least one quart of 2 stroke oil to help blend it out. Maybe a quart of 30 wt as well.
 
I heard stories from old timers that used to put a gallon of unleaded fuel in each 200 gallon saddle tank to prevent gelling in the winter. I have never tried it, but have heard many stories about doing it. That was of course the older "regular" #2 diesel, not the newer ULSD.
 
I would say put enough 2 stroke or conventional oil in it as you feel would ease your mind and run with it...

2 gallons of gas? out of 26-30 i would use about a 1/2 to 3/4 gallon of two stroke and feel safe...

hopefully I'm never going to be confronted with that decision...cause when it happens, panic would ensue and I would then change my mind and put at least a gallon of 2 stroke LOL
 
I would have no real worries about putting in 1gallon of unleaded per 60-70 gallons ULSD, in a dmax, cummins, cat, etc...

That being said, I would be worried about putting in 2 gallons per 32 gallon tank in a truck using one of our old DS4 IPs, which use the somewhat debatable lubricity of the ULSD to stay alive in the first place. Would it kill it? Likely not, but I think I would do exactly what you recommended and pump it all out, just to be on the safe side.

Remember the line about 'there are old pilots, and bold pilots, but no old, bold pilots'? Don't take chances where you don't need to.
 
I know the 1.68 gallons doesn't sound like alot, but in a 26 gallon tank I was worried that I would be taking a chance that I really didn't have too......Opening the line from the LP wasn't all that difficult and seemed like a small price to pay for peace of mind. Also the LP kinda makes easy work of pumping a couple of gallons out of the tank....I guess I just didn't want to give the IP any reason to crap out on me, so I played it safe.

BTW, even Tim said I would probably be ok if I just topped it off, but also said, "If you could get it out....Do it".........So thats what I did.

Thanks again Tim for answering the phone and calling me back at 11:00pm.
 
Brooklyn Tow said:
I know the 1.68 gallons doesn't sound like alot,
Click to expand...

It isn't/ Diesel fuel contains slightly over 5% gasoline as a component, a tad little bit of a smidge more like that will make no difference, none. Simply grab the right handle and continue to fill with diesel, get somebody near by to slap you one, and off you go.
 
from: http://www.turbodieselregister.com/mixing_gasoline_and_diesel.htm

Gasoline and alcohols hit diesel fuel right where it hurts the most. Those light thin fuels will lower the cetane number and lubricity. To explain how octane and cetane DO NOT work together, I’ll have to review more crude oil and fuel fundamentals.

The light distillates that gasolines are made from have a natural high-octane index. The middle distillates that diesel fuels come from have a high cetane index. The octane and cetane indexes are INVERSE scales. A fuel that has a high octane number has a low cetane number, and a high cetane fuel has a low octane number. Anything with a high octane rating will retard diesel fuel’s ability to ignite. That’s why each fuel has developed along with different types of engine designs and fuel delivery systems. Gasoline mixed in diesel fuel will inhibit combustion in a diesel engine and diesel fuel mixed in gasoline will ignite too soon in a gasoline engine.

A lot of old-time mechanics added some gasoline to diesel to supposedly clean the carbon deposits out of the cylinders. I have never read anything that said it worked. Gasoline will make the fuel burn hotter, and hotter burning fuels burn cleaner. That’s probably where the theory got started. In the older diesel engines that belched lots of black smoke even when properly tuned, the result of adding gasoline was probably more white smoke instead of black. This might lead one to believe the engine was running cleaner. Maybe so, probably not. Here’s what happens.

Gasoline will raise the combustion temperature. This might or might not reduce carbon deposits in the cylinder. This also might or might not overheat the injector nozzle enough to cause coking on the nozzle. That’s a clogged injector tip in layman’s terms. The fuel being injected is the only thing that cools the nozzle. Diesel fuel has a lower combustion temperature than gasoline. The fuel injectors depend on the fuel burning at the correct rate and temperature for a long life. If the combustion temperature is raised long enough, the gums and varnishes in gasoline will start to cook right in the fuel injector and turn into carbon. These microscopic carbon particles will abrade the nozzle. High combustion temperatures alone will shorten fuel injector life, gasoline makes the problem worse.

Gasoline and alcohols do have an anti-gel effect on diesel fuel, but these fuels are too thin and will hurt the lubricity. Alcohols work as a water dispersant in small amounts, but also attract water in large amounts. Diesel fuel is already hydrophilic (attracts water) so why add to the problem. The old timers got away with this because high sulfur diesel fuel had enough lubricity to take some thinning. Today’s low sulfur diesel fuels have adequate lubricity, but I wouldn’t put anything in the tank that would thin out the fuel, reduce lubricity, or attract water.
 
btfarm said:
I'd say you made the right call (in more ways than 1) Louis.
Click to expand...

I'm very fortunate to have the phone # to the 6.5 emergency tech hotline....and it's service with a smile, LOL.

Also from what Ashton said, seems that gas is a little more harmful than most people think....but again, the amount and the diloution ratio plays a big role in the line being crossed as far as doing damage.....in any event, I'm just happy that I dodged a bullet.

I hope this disscussion helps someone else that has a gas in diesel situation.
 
the amount and the diloution ratio plays a big role in the line being crossed

Also it's not like you are doing this every time you fil up. At least I hope not!
 
I'd find the jackass who thought it was ok to put gasoline in my tank, and make him clean the damn tank out until it was spotless. Just another reason why I pump my own fuel, you just can't trust people. Especially the kids they have working at the gas stations these days who don't even know what diesel is.

Great thread to start Tim, hopefully this will help out alot of the people in the event they pull this fatal... "whoops" Definatly not something you want to happen too you.

As far as solving the problem I like the above answers. The safest would be to just pop a wrench on the lift pump Outlet fitting(going towards the engine), unhook it and drain out all of the fuel in the tank. Add a bit of 2 stroke and fill her back up with DIESEL fuel.
 
Considering there are members, and militray run JP8 jet fuel as an option I would say a gallon of gas in something isnt going to be that bad. I would just add a full quart of 2-stroke oil, if it was only a gallon or two. I am not usually so empty that I would just have to pump a few gallons out. Theres like 4 gallons left when mine says empty even.
 
Jet A-1 is a kerosene grade of fuel suitable for most turbine engined aircraft. It is produced to a stringent internationally agreed standard, has a flash point above 38°C (100°F) and a freeze point maximum of -47°C. It is widely available outside the U.S.A. Jet A-1 meets the requirements of British specification DEF STAN 91-91 (Jet A-1), (formerly DERD 2494 (AVTUR)), ASTM specification D1655 (Jet A-1) and IATA Guidance Material (Kerosine Type), NATO Code F-35.

JP-8 is the military equivalent of Jet A-1 with the addition of corrosion inhibitor and anti-icing additives; it meets the requirements of the U.S. Military Specification MIL-DTL-83133E. JP-8 also meets the requirements of the British Specification DEF STAN 91-87 AVTUR/FSII (formerly DERD 2453). NATO Code F-34.

Avgas is gasoline fuel for reciprocating piston engine aircraft and is not to be confused with Jet Fuel of any kind.
 
My point is that JP-8 is kero based, and therefore not useful as a measure of comparison in this situation as far as I can tell.
 
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