Fuel additives? Yes or no

[doublewide]

I attended a forum for new PDQ/Antares boat owners, run by the Yanmar representative, for the purpose of training the owners on proper care of their diesel engines.
The question of fuel additives came up several times, and each time the response was the same, "KEEP YOUR FUEL TANKS FULL." Nobody was able to induce the Yanmar representative to endorse ANY fuel additive. All he would advise was to keep the tanks full to keep water (condensation) out of the fuel.

Having said that, since we lay our boat up 8 months of the year, to preserve the fuel in our full tanks, we do add biocide and fuel preservative at lay-up. For 12 years we have had no fuel-related or engine-related problems.

[lvictorlucas]

It looks like you got a lot of testimonials and opinions. Since you asked a serious question here is an answer based on some of my typical assumptions for you:

1) Always try to get fuel from a busy location and not just after their tanks are filled
2) If you can't then filter it before it goes into the tanks (small holding tank with lift pump)
3) Add biocide
4) Add Diesel preservative
5) Try to keep one know good tank of fuel in reserve
6) Empty the water seperators so you can tell if you got fuel with water quickly
7) Rig a spare lift pump to the water separators so you can detect contaminated fuel quickly before you leave the dock (and your backup lift pump is always ready to go)
8) Rig a pressure gauge across the filter to tell when it needs to be changed before the engine is starved of fuel
9) Rig at least two primary water separators filters in parallel so you can switch them quickly
10) Rig 10, 5 or 2 and 0.5 micron filters in series before the fuel gets to the high pressure injection pump
11) Try to keep the tanks full
12) Rig a dehydrator filter to the air vent and check it regularly
13) If you have the opportunity install a water sump and pickup to the lowest point in each tank (you can use the backup lift pump and primary filter when you topoff the tanks
14) Use the backup lift pump to transfer between tanks if you are going to be on a long tack
15) Don't forget to switch the return line when you switch tanks
16) Always carry plenty of spares filters for all you filter types
17) Unless you have a problem don't worry about octane booster but carry some incase need it on some primitive remote island

That's probably enough to get you started.

[boat driver]

refiners do not put additives into fuel as final use may prohibit.

additives are a bit of research to pick between the snake oil and the true stuff.
Among the issues is the reason- and the method of individual fuel storage.
biobor- the fungicide developed for the Vietnam war kills everything- but then it sinks to the tank bottom -
Fuel Right causes the muck to emulsify and move tot he strainers- aka the tank should eventually be clean.
most important to understand is the users that have had to clean u a bad diesel tank tend to believe in additives. Those who have never had a problem tend to change thier minds post a dirty tank.

[sailmac]

I am no petroleum engineer, and what I learned about diesel fuel came more from a real life experience with my RV (500hp Cummins ISM) than the Yanmars on the boat. When we bought the RV it had sat for 3 or so years. Sure enough, about 150 miles into our inaugural trip the filters clogged. Fortunately, we were in Charleston, SC and were able to get someone to polish the fuel, and clean the tank at the same time. His business was almost entirely marine, and he took pity on a holiday-stranded family. As he worked I watched and listened. He used the fuel in the tank to “pressure wash” the tank and simultaneously polish the fuel using filter after filter. As he explained to me, the way modern diesel is made it begins to revert to its natural state almost immediately (basically asphalt), and this process is visible to the naked eye in about 9 months. There are products (additives) to slow the process but none prevent it. I asked him about algae and condensation and his answer was they are rarely the problem (remember where he lives). Proper fuel management is your best defense. Burn it as soon as you can. Not one problem after this experience.

[KiwiKen]

Originally Posted by redneckrob

Well first off jet fuel and diesel are the same fuel. In fact, pro tip for you, when I'd deployed on cutters in the Coast Guard and we'd have to get fuel in Central America the cutter would order jet fuel and use it for the main diesel engines because you were far more likely to get crappy fuel if you ordered diesel.
Second, it's a perfect example that it's simply not true that the refiner will put in any additives that might be needed for your specific application, whether that's an icing inhibitor for jet fuel or an algicide or biocide that's needed if your fuel sits for a long time and not needed by the vast majority of diesel users who run through the fuel in their tanks in a matter of days or weeks.
Just for future reference, I (and many others) like to make use of examples, references, and similarities, so taking our words absolutely literally is likely to lead to confusion at best. Perhaps if an absoutely literal interpretation of someones post doesn't make sense it might be useful to ask ones self if this is an example, a metaphor or the like rather than assuming they're a moron advocating that everyone put Prist in sailboat diesel in the Caribbean to prevent freezing in fuel lines (although I suppose it wouldn't be a bad idea if you live anywhere cold).

If you were aware of the damage that fuel fungus can cause to alloys if there is water in Diesel or Aviation Turbine Kerosene, you would seriously consider a biocide additive to fuel that may sit round for any time. The fungus does damage to diesel injectors, and the damage that it can do to aircraft structures is immense, alloy tanks, (especially aircraft with wet wings like the C130), in fuel lines and fuel pumps. Methyl Iconal is one product used, the RAF used FSII.
The problem is more marked in tropical and third world countries



The danger of Fuel fungus arises where there is water in the fuel, this can be mitigated on a yacht by fitting a water separation filter in the Fuel line, Fleetguard ( a Division of Cummins) make a good water separation filter and sell s a Filter head to plumb into fuel lines. A cheap investment in comparison with the cost of replacing injectors. The Fuel fungus should not cause corrosion to Stainless steel, but aluminium alloys definitely.

[MartinR]

Originally Posted by redneckrob

Well first off jet fuel and diesel are the same fuel.).

No, they are not. Jet fuel is kerosene which is much lighter, has a lower flash point, and will destroy your injection pump quickly, as it has very bad lubricating properties. Yes, some diesels can run on it, but not the normal small boat engines.

[Lepke]

Kerosene may be where jet fuel started, but JP1, 2, 3, etc were all changes in the formula. Kerosene is s close to #1 diesel but not the same. Some people run kerosene in diesel stoves because it burns cleaner.
I use a fuel additive every fueling and never had fuel problems in 60 years. Before the EPA fuel was better, more lubricity, better burn, much more stable.

[redneckrob]

Originally Posted by MartinR

No, they are not. Jet fuel is kerosene which is much lighter, has a lower flash point, and will destroy your injection pump quickly, as it has very bad lubricating properties. Yes, some diesels can run on it, but not the normal small boat engines.

Well again for the purposes of this thread, jet fuel and diesel are indeed effectively the same thing. We were discussing additives, and I was answering the question "What does jet fuel have to do with the subject?" as if I'd started talking about olive oil or something similarly completely unrelated. I was simply explaining that additive use in diesel and jet fuel are very similar since they're very similar. (See my explanation of difficulty in operating in the world using absolute literalism).

But, to switch topics, first off the various grades of diesel, jet fuel, and home heating oil are all very closely related and mostly interchangeable in the way that gasoline and diesel, for example, aren't (although I do know of a crew that successfully flew a Coast Guard helicopter for 2 hours on a 75/25 mix of Jet-A and Avgas!). When talking about things like flash point, for example, you'll find that JP-5 has a flashpoint of 60C, exactly the same as the IMO SOLAS standards for marine diesel. You can throw a match in a bucket of either at room temp and it will go out before it ignites the bucket. There is slightly more lubricity in diesel than jet fuel, so given the choice you'd want to use diesel, but a diesel won't suffer long-term damage if you put a few tanks of jet fuel through it, not even the pump. Obviously folks smarter than you or I who spend their lives doing nothing but studying this determined that it was better for our CG cutters to deal with the lower lubricity in a wide variety of main diesels and generators than potentially bad diesel, again as an example. You can find threads miles long on various auto forums discussing the intricacies of this, it's right up there with "What's the best anchor" question here, so probably not worth diving any deeper into.

And of course when it comes to the thought I was replying to "As to other additives, myths die hard. Diesel is refined and all the additives for anything people worry about has already been added.", the differences between diesel and jet fuel are irrelevant when pointing out that indeed there are numerous specific applications that require an additive the refiner would not have added and providing a specific example.

[redneckrob]

Originally Posted by Lepke

Kerosene may be where jet fuel started, but JP1, 2, 3, etc were all changes in the formula. Kerosene is s close to #1 diesel but not the same. Some people run kerosene in diesel stoves because it burns cleaner.
I use a fuel additive every fueling and never had fuel problems in 60 years. Before the EPA fuel was better, more lubricity, better burn, much more stable.

I've pointed out to you already in another thread, in excruciating details with dates and formulas, that the EPA did nothing to impact diesel fuel as you seem to think it did (http://www.cruisersforum.com/forums/...-210376-3.html). What will it take for you to stop repeating this falsehood, which actually is a myth?

[thinwater]

I've done a lot of additive testing (chem engineer), both lab and field:


* There are few/no standards for additives. There have been efforts, but too many mixed motives. Thus, it is perfectly legal to sell snake oil. This is true of most additives (oil, gas, diesel).
* Biocides must be registered as pesticides. While this is no guaranty, it costs money to register. I have never tested a registered product that did not work well.
* Fuels are treated at the refinery, for normal storage (a few months at most). If you keep the same fuel in your boat for years, you need additional stabilizers. We'll start with the fact that your boat probably has copper/brass fittings, which are a sludge catalyst, and are forbidden for long term storage by ASTM and every major diesel engine manufacturer. Google stand by generators.
* Most people buying additives don't know what the additive is for. Bugs? Oxidation stability? Corrosion? "Performance?" Cetane sounds clear... but testing tells us that may don't actually work.


Without writing an infomercial, stick to OEMs and a few major brands. They work. Off brands are 50/50 on a good day, and some make it worse.


One last thing. Additives prevent problems, they do not fix problems. if you have bugs and add a biocide, the bugs will die, slough off, and clog everything. Keeping the fuel dry and using a preventative dose (both are required by law for jet fuel) is the answer.

[S/V Illusion]

Originally Posted by redneckrob

Well again for the purposes of this thread, jet fuel and diesel are indeed effectively the same thing.

Incorrect premise. They are not (the “same thing”). That is another example of a myth often perpetuated but always unfounded.

Additives are a ‘bandaid’ at best and unnecessary in marine fuel unless other avoidable problems such as water are not effectively prevented.

[sail sfbay]

From personal experience my Hunter sailboat diesel fuel tank got contaminated with algae due to insufficient dosing with diesel fuel additive, e.g., Starbright Star Tron treatment to disperses moisture to help prevent bacteria and algae growth, while stored for 3 years while overseas. Had to get the fuel polished and primary and secondary fuel filters changed out prior to and after polishing. During this same 3 year period my Ford F-250 was stored with a full fuel tank and recommended diesel fuel additive treatment and did not experience any contamination.

Another personal experience after purchase of a Sprindrift Motoryacht I discovered the 4 fuel tanks to be contaminated with algae due to inadequate fuel tank management by the previous owner. I had to polish the fuel tanks and replace the fuel filters.

Since I do not have an installed spare primary fuel filter I use Star Tron fuel treatment on my Hunter 46 with 100 gallons of fuel to mitigate the risk of plugging the primary fuel filter since the fuel tank turnover is very low. I also keep the diesel fuel tank topped off to keep moisture out.

[CarlF]

My understanding is that US diesel was substantially reformulated in 2010 for environmental reasons - so experience from before then isn't really relevant.

I'm told that current US diesel has lower cetane (as low as 40) than European diesel or other parts of the world. Most marina diesel pumps don't show a cetane number and I'm not sure I'd believe it if they did. Cetane also drops if the fuel sits in the marina tank (or boat tank) for a long time.

For most engines (especially newer ones) 40 is supposedly fine. However some Yanmar manuals call for 45 cetane - but obviously there are an awful lot of Yanmar's in the US running happily at less.

There's a potential problem if the diesel you get is out of spec for some reason and has less than 40 cetane. An argument could be made that pushing the cetane up to the level of European diesel is a good idea but I think few do this. Most Cetane "boosters" don't have enough in it to substantially raise the level.

When diesel was first reformulated there was a concern that the lower sulfur would reduce lubrication so many additives brag about lubricity enhancers. But I haven't heard that new fuel has caused troubles in this regard.

It certainly doesn't hurt to add some additives but is not likely to help. Mack Boring - who is the master US Yanmar distributor for the East Coast - does carry and recommend a line of additives.

And Valvetec fuel which seems to be at about half the major marinas on the East Coast has additives already in it - for biocide, water dispersal, lubricity, and stabilization. I've never heard anyone recommending against Valvetec fuel because of these additives. I also haven't heard any hard evidence that it helps - except maybe for the biocide (see next point)

I researched this a few years ago and bought some Fuel Service Diesel Klean which was highly rated (supposedly). All of these treatments have about the same ingredients. Diesel Klean is available at Walmart and cheap. I doubt it does any good but I'll sometimes add some if the fuel isn't Valvetec which has additives.

BUT - anyone who has ever experienced an algae fouled fuel tank knows how important a Biocide can be. Not for the engine but for the filters. The algae causes fuel filters to foul extremely quickly and its hard to get rid of it without opening up the tank for a professional cleaning. I use Biobar Jr but there are other good brands. I put in about a tablespoon per tank fill-up.

It's best to start the biocide when the tank is new and clean to keep anything from starting. If you start it later after your tank is already fouled, the biocide may cause a huge amount of algae to die and fall off the tank walls all at once - usually the first time you go into rough water and slosh everything around. Carry a case of fuel filters on your first trip.

[redneckrob]

Originally Posted by S/V Illusion

Incorrect premise. They are not (the “same thing”). That is another example of a myth often perpetuated but always unfounded.

Additives are a ‘bandaid’ at best and unnecessary in marine fuel unless other avoidable problems such as water are not effectively prevented.

Perhaps then you could iterate the differences between jet fuel and diesel that are relevant to the points I made?

Sure, if we all burned our diesel within weeks of getting it and had a magic system to prevent getting fuel with water already in it or ensuring it never got into the system after we pumped it, we would be able to prevent any stability or growth problems. I know it's been hard to grasp examples that don't involve exactly diesel fuel so I hesitate to again use this example... but we take extreme care with jet fuel in aircraft, to the point of daily chemist tests of the fuel in the fuel farm and each aircraft's tanks by a dedicated fuel farm expert, go/no go filters at fill points, stripping with a professional level stripping system multiple times per week, and we burn the fuel in a matter of weeks from delivery from the refinery. And still, after that insane amount of care that no marine user would be able to take, we add Prist because there's still a real possibility of water in the fuel.

So in imaginary world where it's possible to prevent all water from entering fuel and fuel never sits, yes, the literal statement that the absence of water in fuel avoids problems is correct. For those of us living in the real world, there are additives that do exactly what they say they do and can be invaluable in many circumstances. That's not a "myth", it's what we pragmatists call reality.

I'll leave you with a relevant helicopter joke. A helicopter pilot got lost flying around Seattle above the clouds, and all he could see was a building poking up through the overcast layer. He hovered next to the building and wrote in giant letters on a piece of paper "Where am I?". The people in the building wrote back on a piece of paper "In a helicopter!". The pilot instantly knew where he was and descended through the clouds to land in the Microsoft HQ parking lot. His passenger asked how he could possibly have known where he was based on the exchange. He replied that he knew there was only one place in the Seattle area where a whole group of folks would provide an entirely correct but at the same time entirely useless answer, so he clearly knew he was hovering next to the Microsoft building.

[sail sfbay]

I apologize for going slightly off the original post but thought the forum might be interested in the following:

Ultra-low-sulfur (15 ppmw) diesel fuel was required by the US EPA in on-road diesel fuel sold in the United States since October 15, 2006, except for rural Alaska which transferred in 2010. California has required it since September 1, 2006.

You might find the following link on diesel fuel specifications (including cetane and lubricity specifications; note no biocide specification) in the US (pg 46), EU (pg 48), etc, and additive use (beginning on page 83). Note the US has a lower cetane specification than EU due to different vehicle diesel engine types.

https://www.chevron.com/-/media/chev...ech-review.pdf