• Untitled Document

    Join us on March 29rd, 7pm EST

    for the CBEC Virtual Meeting

    All EYO members and followers are welcome to join the fun and get to know the guest speaker!

    See the link below for login credentials and join us!

    March Meeting Info

    (dismiss this notice by hitting 'X', upper right)

Diesel Fuel additives

saildad

Member II
Hello Vikings
Our new boat(Catalina 42) has a Yanmar 50hp Diesel. My 74 E35 MKII has had an Atomic 4 gas engine all these years so I have never had to learn about the care and feeding of a marine diesel engine.
Where can I find info about additives? I have talked to people and they use them everytime they fill up. The boat has a 38 gallon fuel tank. I can safely say it will be a very long time in between fill ups for me.
Any help would be appreciated.

Capt Bill
2000 Catalina 42
Our Porpoise
Formerly 74 E-35
On Porpoise
(note the name change...the Fiance writes half the checks so I had to go with a slight name change :egrin:)
Channel Islands Harbor
 

treilley

Sustaining Partner
I don't believe in them. I fill my tank once in May, top it off in September and drain it/inspect it in November. I never find anything that would lead me to use these additives. The fuel is always clean with an extremely small amount of dirt(barely visible) and no moisture. I drain it into my home furnace tank.
 

Rob Hessenius

Inactive Member
Fuel Additives

Captain Bill~

There is some good information on fuel additives in the West Marine Catolog. You will also learn alot from just reading the bottles of diesel additives themselves. Being that you are in California, most likely you will sail year round and draining fuel will be a PIA, you should look into them. I personally do not have a diesel in my boat, but I do have a truck that requires that type of fuel.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
I recall another diesel discussion previously on this Board where a member stated that he added a gallon of kerosine to each tank of diesel and that he observed it smoking less and starting easier.
(This was in a diesel forced air furnace thread, as I dimly remember.)

I do add a little "Biobor" microbicide to each fill-up to ward off growing things in the tank...

Loren
 

Gary Peterson

Marine Guy
More important than using additives is to keep your tank free of water.
In my opinion, using additives is a waste of time and money. If too much is used then one could have nozzle plugging issues. No water in tank = no critters growing in your tank. The critters grow in the fuel and water interface line.
 

Brookelise

Member II
Fuel additives

saildad: Congratulations on your new boat. We use three additives: StarTron, which keeps fuel clean with an enzyme, dissipates water, reduces smoke and eliminates carbon buildup; Biobor, which kills fungus and microbes; and thirdly, a cetane/octane booster (from an auto parts store) because of the switch to low-sulfur diesel fuel under the new regulations. One of the benefits of Startron is that it's eliminated any soot from the transom. You can also get a Racor fuel filter funnel to pour your fuel into. This filters out any water. I'd recommend them all. -- Brooke
 

rwthomas1

Sustaining Partner
Everyone has an opinion so heres mine:
I like additives for a few reasons. They do offer a certain level of protection from water in the fuel that gets there from condensation. I particularly like Stanadyne Performance Formula, the blue bottle. It is hard to find, intended for over the road trucks, etc. I have also noticed a wide variation in the quality of diesel fuel although the introduction of ULSD has seemed to improve overall quality/uniformity of the fuel. Lubricity of the fuel is another issue. Some diesels have injection pumps that are lubricated ONLY with the fuel flowing through them. These IP's are not overly happy with the "dry" ULSD. The key is knowing what you are putting in your tank and why. I like the Stanadyne or Howes Lubricator products as they increase the cetane rating and deal with small quantities of water. I can prove 1 to 1.5 mpg improvements using this stuff in my terrestrial diesels. Seems prudent to add the recommended dosage to my boat tank as well. The one thing I don't add is Biobor. Last time I spoke to the injection shop I use they stated that Biobor is thought to leave deposits on the injectors with constant use. Checking the fuel filters regularly and being very careful about the quality of the fuel you use will usually keep the fuel bugs at bay. I should also add that I like biodiesel fuel blends but since biodiesel is hydroscopic you really need to pay attention and keep the tank as moisture free as possible. RT
 
Last edited:

Gary Peterson

Marine Guy
Rob,
ULSD has a lubrication additive added to it by the direction of the government. There is no issue using it with any injection system-in fact-the lastest 2007 over the road highway diesel engines have the tightest clearances in the injection systems ever. This is needed because emmission directives are so stringent. Wait until 2010 for diesels!!! You haven't seen anything yet.
On the point of having Stanadyne or Howe's Lubricator increasing your mileage 1 to 1.5 mpg is simply not believable - sorry. If that ~ 5% increase was valid the diesel engine manufacturers would be knocking on their doors. We never saw this improvement in our test cells at DDC where we could see minute improvements in BSFC. Injection shops don't have the technical knowledge chemist and test cell performance engineers have. Don't get me started on magnents !!!!!
 
Last edited:

tilwinter

Member III
additives and asphaltene

Everyone has an opinion in this arena.

No discussion of diesel fuel is complete without mentioning ASPHALTENE, which is the black substance which spontaneously precipitates out of diesel fuel. It is described as "algae" or "sludge".

If you are curious, put five gallons of diesel in a yellow gerry can and set it in your garage. In several months you will have a thin black layer of asphaltene on the bottom of the can. If you then shake the can, flakes of asphaltene will come off of the bottom and circulate in the diesel. This is what happens to your fuel tank in a sea-way, and will clog your filters and stop the engine.

I put Pri-D in my fuel to help keep the asphaltene dissolved in solution.

If I were energetic, I too would drain my tank every winter, and start with fresh diesel every spring, but I would still add the Pri-D.

I also have my tanks cleaned on a regular basis. The guy who does my tanks says that he usually gets called AFTER the engine has stalled due to clogged fuel filters, rather than before.

There is no substitute for clean fuel in a clean tank.
 

treilley

Sustaining Partner
Now that we have some interesting opinions on the subject I need to confess that I did not drain my tank last fall. I actually let it go thru the winter until May to see what it would look like after a full year of non treatment. I left the tank in Nov. 1/4 full. In May I opened up my inspection port only to find the fuel looked nearly perfect so I did not drain it then either. Again, there was no moister or sludge at the bottom of the tank. There was a very thin dark line about 4 inches long along the seam. I assume this is the ASPHALTENE. But there was not enough there that would cause an issue at that point so I simply used a hand pump to remove the little that there was from the bottom.

It takes me about an hour to open the tank and pump it into jerry cans and dump it into my furnace tank. It will remain part of my fall maintenance.

Just to stir the tank a little more, I feel a lot of the diesel additives out there are little more than snakeoil. Not all, but a lot.
 

u079721

Contributing Partner
My two cents worth......

I took a diesel maintenance class, and the mechanic said to NEVER use additives that are intended to keep the water suspended or dissolved, as it could blow out the tips of the injectors if too much water got into them. Sounds reasonable I guess. He also suggested we all use Biobor to keep the sludge down.

So all I used for most of the time I owned Rag Doll was just Biobor. The last few years I also added Pri-D to help reduce the soot on the transom, but I'm not sure whether that really helped or not. Even though we probably used over 200 gallons a season cruising, most of the fuel sat in the 54 gallon tank from October through the following July, so we worried a lot about sludge. But whether it was the Biobor or good luck we never had any sludge that I could find. YMMV.
 

Emerald

Moderator
I've been taking a little different tack on keeping sludge etc. down. Since I use so little to get up the Severn to The Bay and set sail, and sea state rolling you around on the Chesapeake is pretty non-existant, I go for only having about 10 gallons in the tank. This is more than enough for most of the season. I do realize that there is an argument for keeping it full for condensation, but I figured given my low consumption, it was a toss up on stale fuel versus that. Of course, don't ask some of my faithful crew about getting low on fuel and almost running out. It's happened :rolleyes:
 

rwthomas1

Sustaining Partner
Rob,
ULSD has a lubrication additive added to it by the direction of the government. There is no issue using it with any injection system-in fact-the lastest 2007 over the road highway diesel engines have the tightest clearances in the injection systems ever. This is needed because emmission directives are so stringent. Wait until 2010 for diesels!!! You haven't seen anything yet.
On the point of having Stanadyne or Howe's Lubricator increasing your mileage 1 to 1.5 mpg is simply not believable - sorry. If that ~ 5% increase was valid the diesel engine manufacturers would be knocking on their doors. We never saw this improvement in our test cells at DDC where we could see minute improvements in BSFC. Injection shops don't have the technical knowledge chemist and test cell performance engineers have. Don't get me started on magnents !!!!!

Gary,
I did know that the ULSD had something added but what I was not sure. I do know that I have been using additive long before ULSD was even considered as I have been driving diesels for years. I also know and understand that ULSD is probably the best diesel fuel available simply because it has to work in the super-tight clearances of the very high pressure injection systems on modern diesels.

Thats said, I would like to tell you simply that the 1 to 1.5mpg increases are in fact real. I used to track mpg religiously, every single tank, volume and miles logged. I did this for years in little notebooks under the seat of each vehicle. Yes, I am that anal retentive. The results were proved, back to back and repeated, averaging 6 fillups with additive and six without. I tested each vehicle 3 times over a period of years. Each time the results were the same. The vehicles are a 1984 Mercedes Benz 300D and a 1993 Chevrolet C2500HD with the 6.5TD that currently have 180K and 254K on them respectively. Since these are both older IDI engines is it possible this is a factor? Is it possible that the quality of fuel available when I was doing these tests was poor and the increase in cetane made a difference? I realize that the testing is anecdotal however I wouldn't have said anything if I didn't see the results myself.

One can only go on the recommendations of "experts" When a reputable injection shop states that regular use of Biobor is thought to cause deposits on injectors, well then I don't use it. But then again I have never had an algae or water problem in any of my diesels and thats hundreds of thousands of miles..... Maybe I'm lucky. If I have a problem then I will use it.

I never said anything about magnets and I know they are pure crap.

The other main reason I use additive is gelling in winter. Everyone I know with a diesel has had at one time or another had a problem with gelled fuel. I have towed a few people home to the heated garage to thaw them out. I have NEVER had a fuel related problem, EVER. No gelling, no water, no bugs, injector issues or anything else. All of my diesels will start at 0*F without being plugged in so they are happy and healthy. Well, I did once have a pump seal start dripping on a VW but it had 300,000+miles on it so I think it had a reason....

I probably over-maintain my engines but I have never had any problems in hundreds of thousands of miles in diesels. The only time I have been stranded is a battery that had a dead cell and a starter that had a bad winding. So is it the additives? Can't say for sure but it seems like I'm doing something right. I'm not about to change a good thing, the additives are small change anyway.

RT
 
Top