Fuel additive Dee-Zol / Off road diesel

Mar 31, 2011
62
Leopard 44 Pasadena, MD
Anyone have any experience with Dee-Zol diesel marine fuel additive to combat effects of water in the fuel and inhibit the growth of algae?
https://www.bellperformance.com/fuel-treatment/marine-dee-zol
http://cdn2.hubspot.net/hub/68152/f...ms/DZL_testing_NevadaReno.pdf?t=1389735471000

So far my 4JH4E has been running great. I usually keep my 60 gallon tank three quarters to full. I have a local fuel station tha offers off road diesel containing red dye without paying the road taxes.
Could this type of fuel cause problems for me in the future? Maybe I should check the Sulfur content of the fuel.
 
Sep 25, 2008
7,075
Alden 50 Sarasota, Florida
All diesel fuel sold in the U.S. is low sulfur and is comprised of additives which maintain the lubricity equivalent to that of the old sulfur-containing fuel. The only additive generally recognized as providing any benefit is a cetane booster to meet the requirements of some diesel engine designs.

There is an abundance of studies which can be found to show that keeping the tank full or close to full to avoid condensation is an old myth. The unintended consequence of doing so is stale fuel lower in cetane rating and higher in critter growth plus API recommends, based on industry testing, that diesel older than 6 months begins to degrade.

Snake oil products are abundant and serve only to extract money from your wallet. If you have water in your fuel, it's simple to remove it mechanically while figuring out how it got there and avoid recurrence.
 
May 24, 2004
7,129
CC 30 South Florida
Don, I find a high concentration of water in my fuel and I had always thought it was due to condensation. You know our excessive humidity and then temperature changes around the fall and spring do promote condensation. How much could it result in a vented tank I don't know. I mean the fuel burns fine but the water separator removes about a quart of water every couple of months. The fuel at different pumps seems fine enough and I have replaced the gasket on the filler cap so I do not know where the water is coming from.
 
Jan 30, 2012
1,123
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
Benny

As I am sure you know water comes in forms -- free, emulsified, and molecular. Absent a leak at the fill or the vent line fitting - that is a leak that admits water to the tank when you hose down the decks or if it rains - free water nearly always comes from the fuel supplier to start with. High humidity and abrupt temperature changes can also contribute to free water because emulsified water can 'drop out' forming free (liquid) water.

However, absent a leak tank vent induced condensation will not be much of a player - but it is a contributor because the diesel water content comes in balance with the atmosphere and diesel holds considerable water compared with say gasoline - especially where alcohol is part of the fuel recipe.

The best defense is put in what fuel you need plus a reasonable reserve - no more than that. And try to obtain your fuel from high turnover sources. Your water-in-fuel problems will be substantially reduced.

Additives to combat bio contamination are useful if the tank is clean to start with. Biobor JF is very good and so far as I know all diesel manufacturers approve Biobor - I cannot say about approval of other products. In any case case these additives while effective on bio-contaminants don't help much to dewater diesel.

For more detail and expert discussion on this topic search for this site for 'fuel, water, fuel polish' by Rich H.

Charles
 
Sep 25, 2008
7,075
Alden 50 Sarasota, Florida
A quart of water every 2 months is strange. Are you sure about the volume? The reason I ask is because it can often be difficult to discern the water/fuel interface.

Can't speculate on cause(s) other than to repeat the conclusions reached by others in tests performed by the Navy under API guidelines on condensation formation I tried to replicate in the lab with an aluminum tank I replaced with plastic in our previous boat when living in New England.

In each case, an empty tank sealed during summer was left undisturbed through the winter after which it was opened and the contents measured. Similar tests were performed during the Spring through Autumn period. In none of the experiments, including mine, was there more than 20 milliliters of water found. In one case, the Navy reported no water was found.

Only one test was done by API ( with which I am familiar) simulating an open tank vent which did show appreciably more water forming presumed to be a result of condensation. If anyone does not block their tank vent line, that could provide a path for transport but I personally don't think a quart is possible
 
Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
a. You can install a silica gel vent filter. I've been using one for about 5 years. At the very least, it eliminates the possibility of condensation/absorption.
http://sail-delmarva.blogspot.com/2016/09/silica-gel-vent-filters-dry-diesel-and.html

b. Even better for e-10 which is more sensitive to water. It also reduces evaporative losses which can lead to gum and hard starting due to lack of light ends.

c. Reduces corrosion, which requires water. A serious problem with e-10, which is greatly reduced with additives and very dry gasoline.

Even so, breathing can only be a few ounces per year, probably less, based on the saturation rate of the vent filters. More than I want in my tank, but hardly something you will be able to measure in quarts.

Do we really believe the fuel dock is pumping quart volumes of water? That is clearly ludicrous, as the community would have burned the place to the ground. Commercial guys would burn his home. They don't draw off the bottom and they have water-block filters the same as you do. While I'm not saying it's never happened, they get blamed at least 100 times for every time they are at fault. Seriously, it passes no reasonableness test.

It's the filler cap. It could also be the vent; is it located where it can catch a hard wave slap or driving rain, and is there a good high loop, about 2 feet?
 

NYSail

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Jan 6, 2006
3,048
Beneteau 423 Mt. Sinai, NY
I leave my tank as empty as possible in the winter... less than 5 Gallons.. I run tank low all the time to use fuel. Put 5 gallons fresh in spring. Never any additives other than cetal booster. The racor 500e never has any water...... guess this is where I'm lucky in life.

Fresh fuel is cool!