Fuel and Standing for months...

old-mo

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Oct 16, 2008
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Put the M-home on a SORN a few months ago...

And won`t be taxing it for another month or so... when I parked up there was just over a quarter of a tank of fuel, been started a few times and moved around and battery kept topped up (Put on Charge)..

Normally when parking up I make sure the fuel tank is full.... now...

Should I drain all the fuel (Couple of gallons at most) and dump and refill in case of condensation from standing... or ..

Just top up and let the water filter take away any condensation if there is a water filter or what ever they are called.. or is there NOT likely to be any water (Condensation) in the tank..?

Thanks.. (y)
 

Mikey RV

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I would not worry about it. Think about all them motorhomes parked on forecourts at dealers with just a bit of fuel in, then someone buys it and off to the nearest garage to fill up. (y)
 
Apr 21, 2009
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I have read on USA sites about diesel going off but have not experienced, no heard, of any major problems in UK. I would therefore echo @Mikey RV and @simsy56 and just fill up ready for your travels.
 

poacher

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Aug 10, 2008
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Know “times are hard” ‘cos you are making your CL large enough for ‘us’ big boys :whistle:
but,
I would dig deep and put a dose,or two, of diesel biocide in the tank before you fill up
(Bottle of Wynn’s is about a tenner and is lots of doses)
Will take care of any diesel gremlins that might have sneaked in when you weren’t looking
poacher
 
May 7, 2016
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From my boating days I recall that the problem was not the water itself but that the diesel bug could bloom if there was water present. Hence the advice to keep tanks full to minimise condensation. One boat I bought had a serious invasion of the bug in both tanks and it was one hell of a job to get rid of it. However I think it had been unused for a lot longer than a few months. I believe there are biocides available if you think there is water in the fuel but I would hope that modern road fuels are not infected in the first place.
Does anyone know whether modern diesel fuel comes pre treated?

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DuxDeluxe

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From my boating days I recall that the problem was not the water itself but that the diesel bug could bloom if there was water present. Hence the advice to keep tanks full to minimise condensation. One boat I bought had a serious invasion of the bug in both tanks and it was one hell of a job to get rid of it. However I think it had been unused for a lot longer than a few months. I believe there are biocides available if you think there is water in the fuel but I would hope that modern road fuels are not infected in the first place.
Does anyone know whether modern diesel fuel comes pre treated?
There is no biocide present in normal EN590 fuel. Once you have the dreaded aerobic bacteria it is a sod to remove and might take a few biocide treatments. Having said that, you are pretty unlucky if you get it.

Keeping the diesel tanks full to minimise condensation is a very good idea
 

Feltwell

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Aug 27, 2014
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I'd keep diesel tanks full for all the reasons mentioned above. Diesel doesn't seem to go off - unlike petrol, which is more of a pain, the modern stuff does seem to go off - says the man who has some motorbike carbs to take off and get ultrasonically cleaned due to blocked pilot jets due to standing with petrol in :cry: The petrol evaporates and leaves a varnish like residue that is a nightmare to remove, ultrasonic cleaning seems to the only thorough way to do it. Funny how my old lawnmower never has any problems though after standing all winter, but I guess it is a very crude carb and engine so maybe a bit more tolerant.

Even adding fuel stabiliser doesn't seem to keep petrol fresh for too long any more.
 
Aug 6, 2013
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I'd keep diesel tanks full for all the reasons mentioned above. Diesel doesn't seem to go off - unlike petrol, which is more of a pain, the modern stuff does seem to go off - says the man who has some motorbike carbs to take off and get ultrasonically cleaned due to blocked pilot jets due to standing with petrol in :cry: The petrol evaporates and leaves a varnish like residue that is a nightmare to remove, ultrasonic cleaning seems to the only thorough way to do it. Funny how my old lawnmower never has any problems though after standing all winter, but I guess it is a very crude carb and engine so maybe a bit more tolerant.

Even adding fuel stabiliser doesn't seem to keep petrol fresh for too long any more.
Add two-stroke oil to your last tank of petrol at, say, 50:1. You will not get varnish when the carb (or injection system) dries out.

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May 31, 2015
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when I parked up there was just over a quarter of a tank of fuel,

Tut tut tut , mo , now you know better than that , mate .

If you replace the fuel filter every year , i would just delay the new filter till the old fuel is used up . All diesel contains some water , at worst you will just have a little more than most , either way the filter should still be able to cope with it .

I have never heard of diesel going off . I know many people who top their tank's right off , and leave it throughout the winter with no problems , actually i'm one of them and have been for many years . However petrol is a completely different animal as @Feltwell has quite adequately added , thanks for the little ditto on fuel stabilisers , i normally drain anyway , but i have wondered .
As @Pausim has also quite adequately put it , the problem with diesel fuel is aerobic bacteria . I don't believe it can be cultivated in the short time the fuel is in the tank , it is far more likely to be imported in contaminated water that's always present in diesel , even the high quality stuff , and that is why i believe it's so difficult to eradicate . This is the reason i'm fussy where i refuel and try to limit the amount of water i do have to take , there are treatment's about , but i think it's better not to catch the thing in the first place .

As @DuxDeluxe has so eloquently put it , it's a sod to get rid off .
 

PeteH

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Not knowing what your `van is, nor actually how long it has been standing. All I can tell you is that when I was living in mine, for up to a year whilst doing a bungalow gut out and refurbishment, I had a part full tank of diesel, for most of that time. She Fired up OK first time and the "water in fuel light" stayed off. After which we went off to Spain for 3 months. I was forced to leave the Winnebago in storage one year for nearly 9 months, due to SWMBO`s medical issues, with a tank full of Unleaded, with just some "generic fuel treatment" in it. right through a Texan winter. Again no issue when I started it up, and we took it all the way to Wyoming that year.

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filopastry

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With petrol there is a marked octane drop over time and the risk of bacteria much more so with the modern lead free. In microlighting we never hold fuel in the tank for extended periods even with two stroke oil in. If it is in the tank more than one month, I will drain it out and use it in the garden machine, but then it is a little more important in the air.
PETROL.
https://www.bp.com/content/dam/bp-country/en_au/media/fuel-news/petrol-life-vehicle-tanks.pdf

DEISEL.
https://www.bp.com/content/dam/bp-country/en_au/media/fuel-news/lifetime-fuel.pdf
 
Oct 27, 2017
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Jetlag, you don't fly enough. Fly it every week, if possible. Better for you and the plane...
 
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