Return to the Torresen Marine Home Page

Think Twice Before You Add the Additives – A Caution About Fuel Additives

The companies manufacturing fuel additives must be doing a terrific job marketing their product. This has to be the case since so many people seem to want to add something extra to their fuel tank.The best thing to add to your fuel tank is simply good quality fuel … and nothing else. Yes, I did say no additives. There is nothing better than clean, high quality fuel in a clean tank.Most every fuel contamination problem is related to water in the tank. It is virtually impossible to keep it out but occasional maintenance on the tank will get rid of it. Maintenance of the fill cap o-ring will keep most water out. Running out of fuel (or pumping it out of the usual fuel line) does not get rid of the water on the bottom of the tank. An effort must be made to get the water out of the lowest point of the tank.I guess most of us like what’s easy, sort of like a Diet Coke with a Big Mac. It doesn’t work. Unfortunately most boat yards don’t understand the problem nor do they know how to apply the remedy.There are many believers in additives. I’ve have heard people say, “I’ve been using Brand X for five years and have never had a problem”. Perhaps that was a water free tank that needed no additive. The fuel makers say that they put the right stuff in. The additive makers (all of them) say that you have to use their product. If your fuel has no problem, leave it alone. If it does have a problem, get it out of there and put in good fuel. Good fuel is the second most important thing in diesel maintenance, after the lube oil.

I know that too much of the wrong additive can cause problems. There is word that some additives react with other additives. I personally would rather play safe and keep my tank clean.

It seems foolhardy to me that many owners gamble with a ten-dollar jug of additive to try to resurrect fifty dollars worth of fuel when the heart of a $10,000 engine is at stake.

Share or bookmark this story:
[Digg] [Reddit] [] [Facebook] [Technorati] [Google] [StumbleUpon]

This entry was posted on Monday, February 25th, 2008 at 3:10 pm and is filed under Engines, News From Torresen Marine. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

8 Responses to “Think Twice Before You Add the Additives – A Caution About Fuel Additives”

  1. TONY ORELLY Says:

    I read the article, but what about storage over the winter, don’t you need to add something then?
    What about sticky fuel injectors?
    Please advise.
    Tony ORelly

  2. Tom Plagenhoef Says:

    You leave us hanging with the statement: “Running out of fuel (or pumping it out of the usual fuel line) does not get rid of the water on the bottom of the tank. An effort must be made to get the water out of the lowest point of the tank.” Are there methods that the do-it-your-selfer can use?

  3. Mark Swaine Says:

    I had a problem with a substantial amount of water in my fuel tank a few years ago. I solved it by purchasing a “suck-up” pump and removing the water from the bottom of the tank. The “suck-up” pump looks like an old pressurized garden sprayer, with a handle on top to provide the suction. It comes with a lengthy clear plastic hose that you can send to the bottom of the tank to remove the water. (sometimes you have to improvise with something long and straight attached to the hose.) When you get it on the very bottom, you only have to keep pumping until you have nice pink fuel and no water in the line. (it will be apparent) If you begin every season with this evolution then you should have no fuel contamination during the year (barring some dummy putting water in the wrong fill hole or defective fuel cap gaskets)

  4. jak Says:

    i realize that there is often an access problem with fuel
    tanks, but i don’t understand why fuel tanks don’t have
    a simple drain port at the lowest point, much as on
    airplane fuel tanks. i added a 1/4″ stn stl pipe stub
    & ball vave to mine, it’s easy to occasionaly drain out
    some fuel (diesel) if there’s any water keep draining out
    a little at a time until it’s gone.

  5. Rick Warner Says:

    What do you think about using a service that ‘polishes’ the fuel already in the tank? Would that also get rid of sturred up sediments before they get a chance to clog your (Racor) filters? Are there any services of this type between South Haven, MI and Muskegon, MI?

  6. Gordon Torresen Says:

    Tony – You should have no problems for “a” winter layup. Consider that the temperatures are generally low and the cold takes the place of any helpful additives.

  7. Gordon Torresen Says:

    Tom – Answers to your questions are contained in the following writing. If you have any further questions please let us know.


    One of the main contributors to reliability of a diesel engine is the quality of the fuel. You must start off with a good fuel and then not let it get contaminated. Sometimes, but very seldom, the contamination comes with the fuel. Most all fuel dispensers have final filters on their pumps that will shut down the flow if dirty, or if water is trying to get by. The most common contamination is water. Algae require water to survive and will not be present if there is no water.

    It is virtually impossible to keep water out of the fuel tank. There is always the threat of condensation inside the tank where the moisture in air within the tank is precipitated on the sides of the tank with temperature variations. This can be overcome by not exposing the sides of the tank to the air by keeping them covered with diesel fuel. The usual way for water to get into the fuel tank is at the fill. All fill caps have an O ring to make a seal. If the O ring is defective, the fill becomes a small funnel. Each time it rains or each time the deck is washed, a drop or two of water enters the tank. Over time the accumulation is enough that the fuel pickup to the engine starts to get the water. This usually happens when motoring in a slop where the water forms waves under the fuel and the crests of these waves impinge upon the end of the pickup tube. You don’t know it’s happening until a filter shuts down or, with some filters, the water actually gets to the injectors.

    Water in the fuel tank is often discovered when changing filters. If any water is present in any fuel filter, it indicates that there is water in the tank. Now is the time to take care of it. The water can be removed only by picking it off the bottom of the tank. Pumping out all the fuel through the normal pickup tube will not get the water. Many tanks have a hand hole in their tops that can be removed for access. Others have a fuel gauge sender that can be removed. A definite low spot in the tank must be located. If there is no true low spot, one can usually be made by heeling the boat. The water will have run to the low spot quickly. Now you must go in through the access with a pump tube that is stiff enough so that you can feel when it is in that lowest spot and pump out the water. If algae is present, it will take longer to move and all of it may not be pumped out. The filters will find it later if it exists.

    There are also wick type devices that can be lowered into the tank that will absorb only water. These can be pulled out from time to time and checked. They get replaced when they are full of water. There are chemicals that can be smeared on the end of a stick and the stick can then be inserted to the bottom of the tank. The chemical changes color if there is water present.

    Additives should not be required and, in my opinion, should not be used. If there is no water, no water dispersion medium is needed. If there is no water, there will not be any algae, ergo, algaecides are not required. Some additives react with others forming crystals. Not good. Some additives alter the combustibility of the fuel and can affect the running of the engine, especially when warm. Some additives kill algae but leave their poor dead bodies in the fuel. Other additives claim to disperse the water into the fuel, when this happens some algae go along for the ride with that water. I have not seen an additive that claims to remove the algae’s fecal matter. The refineries make good fuel that contains the proper lubricating qualities and life enhancing additives. That fuel is distributed to the service stations, truck stops and marinas in good condition. Most dispensers deliver it in good condition. Most contamination occurs with the final user. The final user must keep that fuel in good condition or take the proper steps to remove the contamination.

    There is a device, called Algae-X, that “polishes” the fuel as the fuel is being circulated. This, in conjunction with the filters, will clean out any alga that is being picked up and run through the system. . With the return system used with most diesel engines, the fuel is constantly being circulated through the filters while the engine is running. For boats experiencing problems with algae, this may be a good investment. The water must still be removed by other means.

    How does one define “old” fuel? Unless you have completely drained and cleaned your fuel tank, it is probably accurate to state that some of the original fuel is still there. How much it has been diluted (rejuvenated) by new fuel would depend on many variables. If you have a 30 gallon capacity and only use 15 gallons a year, you would cut the old fuel by 50% each year. Considering that many of the larger cruising sailboats have much larger tanks and some don’t burn much more fuel, there is a lot of old fuel that goes sailing. We have seen boats that were in storage for more than five years get launched, new batteries installed, and the engines started as if they had never been idle. Right now I can’t say when fuel is too old. I will do some research and then update this page.

  8. Stanford Matus Says:

    I purchased the smaller size air sterilizer 2 years ago and put it close to my bed. It has helped me enhance my quality of sleeping. I used to have stuffy nostril when allergy season comes and I’ve to take totally different sorts of allergy medicines every year for releasing my allergy symptoms. Now I am drug free. Final 12 months I bought a much bigger measurement of Secure AirSterilizer filter for the house. This air filter did assist lots for clearing the germ and pollen within the air. It additionally helps to regulate spreading the germ if someone in the home has a cold.

Leave a Reply