Diesel Fuel questions

[kingthrob]

Diesel Fuel questions...I Googled these and get different answers. I am new to diesel.

How long does it last without degrading to point that it should not be used?

Is there a difference diesel fuel from Automobile gas station or Marina? Besides price.

What products/additives should be added?

Do you keep extra fuel aboard in 5 gal containers?

Any good advice regarding diesel fuel?

 

[O C Diver]

I don't have a definitive answer for you, but I kept a tank of diesel for almost 2 years during my refit. Didn't use any additives. I'm sure there was some amount of Asphaltene that precipitated out of the diesel, that's easily picked up by the fuel filters. How long a time were you considering?

Ted

 

[kingthrob]

It was just a general question regarding fuel life. I have about 150 gallons of diesel onboard and at approximately 2 gallon burn per hour (I think) I do not expect to use that much in the foreseeable future. 120 hp Lehman. 1974 Marine Trader 34 Sedan.

 

[O C Diver]

It was just a general question regarding fuel life. I have about 150 gallons of diesel onboard and at approximately 2 gallon burn per hour (I think) I do not expect to use that much in the foreseeable future. 120 hp Lehman. 1974 Marine Trader 34 Sedan.

Use your boat more next summer and it won't be a problem.

Ted

 

[psneeld]

75 hours of running isn't a lot of time to burn up in a year or two and if the diesel isn't more than a year or so I wouldn't expect any issues with good filtration.


With your long, warm summers I would add Biobor or any additive that inhibits microbe growth. When I burned through maybe half of it, I would add another fresh 75 gallons or so.

 

[Beekeepergreg]

Water laying under fuel is bad from a bacterial growth issue as well as shutting down your engine in the worst sea conditions. Keep extra filters and learn how to change them.
Diesel is a #2 fuel. Heating oil is a #2 fuel with sulfur left in. Diesel now a days has the sulfur removed and lubricants added. Sulfur was the lubricant.
Try to use old fuel and keep fresh fuel.
Greg

 

[Lostsailor13]

The difference is state highway tax,the diesel at the dock has red dye

 

[BDofMSP]

About a third of the fuel stops last year (and there was a considerable number, driving from Florida to Wisconsin) had undyed fuel. I was very surprised to find this.

 

[timb]

I use this when I think about it .
ValvTect - BioGuard Plus 6

it's good to keep enough diesel onboard to fill you filters about twice if you have to change them and have a pot or bucket to drain the racor or other filter in . i keep one gallon but it will only do my filter once I have a racor 1000. I have only changed it once .I don't know how old this one was but it was nasty .but the vacuum gage was still showing good and no water seen .

 

[Lepke]

Diesel with a good stabilizer will last several years. If stabilizer is added yearly and the fuel circulated until it's mixed in, the fuel will be burnable for many years. Even old fuel, w/o stabilizer can be returned to use with a good additive and circulation. My current boat sat 6 years before I bought it with no stabilizer or mothballing and I renovated the fuel and used it w/o problems.
I use an additive every fueling. If the fuel is going to sit, I add more over time. Today's fuel has poor lubrication, poor stabilization and doesn't burn as well as the fuel of 20 years ago. That's why I use a stabilizer. The one I use also improves the Racor's ability to remove water.

 

[O C Diver]

Diesel with a good stabilizer will last several years. If stabilizer is added yearly and the fuel circulated until it's mixed in, the fuel will be burnable for many years. Even old fuel, w/o stabilizer can be returned to use with a good additive and circulation. My current boat sat 6 years before I bought it with no stabilizer or mothballing and I renovated the fuel and used it w/o problems.
I use an additive every fueling. If the fuel is going to sit, I add more over time. Today's fuel has poor lubrication, poor stabilization and doesn't burn as well as the fuel of 20 years ago. That's why I use a stabilizer. The one I use also improves the Racor's ability to remove water.

So you're going to write all that, and not reveal which additives you use?

Ted

 

[mvweebles]

Well, under the category of "don't try this at home....."

I hadn't run my boat more than periodic starting/running for at least 10-years. Fuel aboard was probably 12 years old. One tank didn't smell like diesel - smelled like linseed oil.

Well, boat is in San Francisco and I'm trying to get to Ensenada, 500 nms south. Turns out that getting rid of diesel fuel is expensive in a place like San Francisco - disposal would be over $4000 for about 200 gallons.

So my mechanic suggested triple dosing with Standyne and diluting with fresh diesel. I added about 80 gals to the estimated 150. I did around 25 hours of sea trials and the old Perkins 4.236 seemed to run fine - I swear, a drunk could piss into those tanks and that Perkins would run.

I went through one set of filters on the way south. The fuel was so bad I couldn't even give it away the the Mexican fishing fleet. Took to a disposal station and paid about $1/gal.

My takeaways: diesel can last a long time. Depends on your engine. I'd imagine a high hp engine that runs a lot of fuel would be a problem. Second, climate probably matters. No way diesel would hold up that well for that long in Florida.

Peter

 

[bayview]

75 hours of running isn't a lot of time to burn up in a year or two and if the diesel isn't more than a year or so I wouldn't expect any issues with good filtration.


With your long, warm summers I would add Biobor or any additive that inhibits microbe growth. When I burned through maybe half of it, I would add another fresh 75 gallons or so.

Adding new fuel to old just prolongs the old.
Run it down as low as possible then add some new, not full, just enough for the next trip. Then when tank is low Much of the old fuel will be gone.

Clean dry diesel will last long time.

 

[Shrew]

How long does it last without degrading to point that it should not be used?

No idea, I use a tank a season

Is there a difference diesel fuel from Automobile gas station or Marina? Besides price.

Yes, diesel for off highway use is dyed red and doesn't have highway tax included.

What products/additives should be added?

Hammonds BioborJF Diesel Fuel Additive
Function: Prevents Filter Clogging due to Organic Growth
Prevents Bacteria, Fungi and Algae Growth, US Coast Guard Certified

Hammonds BioborMD Diesel Fuel Additive
Biobor Reduces Soot, Increases Cetane, Stabilizes and Prevents Corrosion
Anti-Gel and Lower CFPP, Inhibits Corrosion and Restores Lubricity

Sta-Bil for Diesel

StarTron for Diesel

Do you keep extra fuel aboard in 5 gal containers?

No, but if there are chances that you will need to prime your fuel filter on the fly, I would

Any good advice regarding diesel fuel?

Don't let the tanks get so low that you suck air into the system. Don't let the fuel sit for very long (whatever that means) periods of time.

 

[LenBuchanan]

I use the BioborJF and add the the tanks when I fuel up at the end of the season. I also buy Cetane Booster (I think it is called). Silver Bottle from Walmart and add that each time I fuel up.
When I purchased my boat in New Jersey, there was about 1/3 fuel in each of the tanks. I left New Jersey and travelled to Haverstraw NY and filled up the tanks there. On the way back to Michigan, every morning before we left, I would check filters and drain a little from the bottom. I keep a five gallon diesel fuel container on the boat and use that to put fuel in clean juice bottles. I use those bottles to wash out the filter bowl and fill up the bowl after I put in a clean primary Racor filter. I then talk to Marinas along my path and see if I can rid myself of the old fuel with them. So far, I've had no problems.

 

[Simi 60]

We had 10 year old diesel in half full tanks when we bought her in a climate similar to Florida
No biocides used
No clogs or evidence of any crud after several months running that fuel load (I take a sample bi monthly)

I believe the trick is.....

No deck fillers so no water leaks - ours are high in cabin side
Drainable crud sump at lowest part of tank - checked bi monthly
Good filtration
And good circulation - the 855 Cummins pumps about 320 litres/86 gph through the filters so essentially polishing continuously when running.

 

[AKDoug]

Adding new fuel to old just prolongs the old.
Run it down as low as possible then add some new, not full, just enough for the next trip. Then when tank is low Much of the old fuel will be gone.

Clean dry diesel will last long time.

Agreed! When I purchased my boat it had 110 gallons of indeterminate age fuel in it, the boat yard loaned me a pump and two barrels to pump it out. They used the fuel for a diesel drip heater in the boatyard shop, so it was win/win.

I filled with 140 gallons, with a clean filter, and headed North to Alaska. The first tank really cruded up the filter bowl, lots of agitation from the trip to Prince William Sound from Anacortes over the Gulf.

 

[Simi 60]

Ill happily take your old, clean diesel off your hands to feed through our engine
Anyone with old diesel pease send to........

 

[psneeld]

Adding new fuel to old just prolongs the old.
Run it down as low as possible then add some new, not full, just enough for the next trip. Then when tank is low Much of the old fuel will be gone.

Clean dry diesel will last long time.

Got any professional paper links or sources to prove that?


Granted my view is just opinion based on decades of reading the same advice...rarely reading that clean old fuel is a problem and the additives/lubricity by adding new fuel can only make it a better fuel.


I forgot to ad that I would do it with older or low performance diesels.

 

[Arc]

I recently was called to remove 3 large farm tractors out of a barn. All with flats and haven’t been run for over 12 years. We got all running after some head banging. We never added fuel and they all ran perfect .

 

[Lepke]

So you're going to write all that, and not reveal which additives you use?

Ted

Done it many times here and elsewhere. I figured people were getting tired of hearing it.
Archoil, AR6200. Available online at archoil.com, Amazon and ebay. Also in commercial marine stores.

 

[Flatswing]

Agree

I recently was called to remove 3 large farm tractors out of a barn. All with flats and haven’t been run for over 12 years. We got all running after some head banging. We never added fuel and they all ran perfect .

My experience also. If the fuel doesn’t have any water (in the tanks) just run it. Racor Filter changes too often, empty & clean the tanks. Don’t overthink this. Most (older) diesels are extremely forgiving (barring water in the tanks).

 

[FF]

There is a difference in price between auto and commercial (truck stop) diesel, the trucks pay additional road taxes so in most places the auto fill up is cheaper.

Truck stops also post a higher price so they can discount the fuel for customer that buy in volume.

There is a difference between summer and winter fuel, the winter fuel has an additive to prevent gelling , the wax in the fuel stops the fuel from flowing at low temperatures.

This can be added if purchasing southern fuel and driving north in winter.

AS they are delivered to the distribution point by pipeline the red dye is added before delivery.

It is claimed that diesel is better filtered than home heating oil at the distributors , but I have never seen proof.

If filling fuel and there is time , using an external deck filter is a worthwhile process, tho it slows down the fill time.

 

[catalinajack]

All diesel fuel, auto and truck, is taxed at the same rate both at the Federal and State levels so the statement that "trucks pay additional taxes" is 100% incorrect. Stop at any filling station that sells to trucks and autos and you will see that the pump price is the same.

Next: "There is a difference between summer and winter fuel, the winter fuel has an additive to prevent gelling, the wax in the fuel stops the fuel from flowing at low temperatures." Yes, there is winter diesel fuel but it is difficult to find anywhere except perhaps in the extreme northern parts of some US states. It is called No. 1 diesel as opposed to the commonly available No. 2 diesel. I have never seen No.1 diesel for sale in Northern Vermont. So, "southern fuel" is pretty much a myth. No.1 diesel can sometimes be kerosene.

Stated in another response was that sulphur was the lubricant in diesel. Nope. The lubricity of diesel fuel is lessened in the refining process used to remove the sulphur. Additives are used to restore lubricity.

Attached is a lengthy technical document that will answer all questions related to diesel fuel, home heating fuel, and the differences among all of the similar fuels. Very informative.

There is a difference in price between auto and commercial (truck stop) diesel, the trucks pay additional road taxes so in most places the auto fill up is cheaper.

Truck stops also post a higher price so they can discount the fuel for customer that buy in volume.

There is a difference between summer and winter fuel, the winter fuel has an additive to prevent gelling , the wax in the fuel stops the fuel from flowing at low temperatures.

This can be added if purchasing southern fuel and driving north in winter.

AS they are delivered to the distribution point by pipeline the red dye is added before delivery.

It is claimed that diesel is better filtered than home heating oil at the distributors , but I have never seen proof.

If filling fuel and there is time , using an external deck filter is a worthwhile process, tho it slows down the fill time.

View attachment 1610717036103_diesel-fuel-tech-review.pdf

 

[jleonard]

It is claimed that diesel is better filtered than home heating oil at the distributors , but I have never seen proof.
.

I have not read proof, but my experience tells me that it's true. Being a New England home owner for most of my life I have changed many home heating filters and many boat diesel filters. The home heating filters are disgustingly filthy and sludgy and the boat diesel filters are clean. Same with the vehicle diesel filters, very clean.
Like I said, my experience.

 

[bayview]

Got any professional paper links or sources to prove that?


Granted my view is just opinion based on decades of reading the same advice...rarely reading that clean old fuel is a problem and the additives/lubricity by adding new fuel can only make it a better fuel.


I forgot to ad that I would do it with older or low performance diesels.

This is the classic mixing problem of calculus courses.

If you want to have the cleanest fuel in the fewest engine hours do as I said.

To demonstrate take a half empty cup of coffee add water to fill then pour out half and refill. Repeat. How may time do you have to do it before it is clear?

Next take same half cup, dump out most of the coffee, add a small amount of water and dump most out then add another small amount of water and dump.

Which process gets you the clearest water with the least water used (fuel/engine hours) soonest?

 

[psneeld]

This is the classic mixing problem of calculus courses.

If you want to have the cleanest fuel in the fewest engine hours do as I said.

To demonstrate take a half empty cup of coffee add water to fill then pour out half and refill. Repeat. How may time do you have to do it before it is clear?

Next take same half cup, dump out most of the coffee, add a small amount of water and dump most out then add another small amount of water and dump.

Which process gets you the clearest water with the least water used (engine hours) soonest?

If that's your method of science....I can't quite agree with it.


I just like to have the added benefits of 50% fresh fuel as soon as possible...possibly increasing cetane number, fresher additives.....


Maybe they really don't change that much, but I have not seen much in the way of disputing it either.


That's why asked for research links versus the worst example I ever read... if I used a coffee analogy (which is a stretch in any case)...I would drink a half cup of old,cold coffee and add fresh, hot coffee so I could at least enjoy things sooner. Yep, stinks as an analogy...but pretty much we are talking diesel and coffee...the analogy to that would be apples and oranges. If we were only talking color, maybe.


In either case, if running old diesel could be harmful to a significant amount, getting rid of it is better than running a 1/2 or the whole tank.

 

[koliver]

I have not read proof, but my experience tells me that it's true. Being a New England home owner for most of my life I have changed many home heating filters and many boat diesel filters. The home heating filters are disgustingly filthy and sludgy and the boat diesel filters are clean. Same with the vehicle diesel filters, very clean.
Like I said, my experience.

Also a price differential:
home heating oil, Dec 2020, $1.318/l,
diesel at the local gas staiton Dec 2020, $1.099/l,
diesel at Van Isle Marina, after 1000l discount, $1.269/l GST MAY be added to the Marine price, making that $1.332/l.

 

[FF]

"No.1 diesel can sometimes be kerosene."

Kerosene can be used as fuel for a diesel, in an emergency, but needs about 1 quart of engine lube oil for every 5 gallons of kerosene.


Kerosene does work great for truck heaters (Espar & others) repurposed as boat heaters

 

[stubones99]

All diesel fuel, auto and truck, is taxed at the same rate both at the Federal and State levels so the statement that "trucks pay additional taxes" is 100% incorrect. Stop at any filling station that sells to trucks and autos and you will see that the pump price is the same.

Yes and No...
Yes, trucks burn the same fuel at the same price as any other diesel road vehicle.
No, when a commercial truck buys their tags, they get hit with lots more taxes than just a regular diesel vehicle on the road. The heavier they are rated (more axles, bigger engines, longer trucks, etc.,) the more they pay. And, if they run more than a certain number of days in some states, they have to buy tags in the other states, which means more taxes to pay.