Diesel Fuel additives are not new, they have been around for decades, but do you need them? We take a quick look at the myths and lay bare some of the wild claims.
Some readers may recognise the term Snake Oil as the American slang term given to medical products with dubious and unverifiable benefits in the late 1800s, Europe had its own version, “Viper Oil”. Following years of questionable benefits, dubious recommendations and wild claims, fuel additives are often viewed in the same manner.
I spent many years at sea rising to Chief Engineer in the late 80’s. During that time only very occasionally did I see lacquering on fuel pumps but never any fuel bug or lubricity problems. Diesel had not changed for decades and the engines were simple. Yet there were constant recommendations to dose with ‘fuel saving’ and ‘sludge busting’ additives amongst others, at dose rates so small they would bemuse the best brains at NASA. Any additives required were put in by the suppliers as margins and business was good
Sludge busting - Why I asked myself, the tanks were always perfect and the filters always clear. Fuel saving claims up to 10% - How? If it was that good no one would have to sell it as owners would be beating a path to the supplier’s door. The reality left few seeing any benefits and resulted in the belief that additives were deemed unnecessary - after all diesel is diesel, isn’t it?
Not any longer. Fuel has changed completely, refiners are constantly under pressure to cut costs. They now refine 80% more from a barrel of crude than they did in the 1980’s and these barrels originate from fields which were deemed uneconomical and of poor quality in the 90’s. As a result today’s crude has more sulphur and undesirable elements which pose greater challenges to the refiners as they endeavour to supply a product to meet ever increasing environmental legislation and the demands from the engine builders. All at a time when fuel margins have been squeezed to a minimum, business is not so good now and additives are a cost, so only the bare minimum is added to meet specification.
For decades there have been only two additives readily available, one to stabilize the fuel and one to kill bugs, and there are a multitude of suppliers who promise everything from both. Read more here.
If you have sludge in your filters then yes you need to treat your tank as you have ‘Diesel Bug’. There are two types of diesel bug treatments; enzyme and biocides. Enzymes don’t kill the bugs, they remove their food. Biocides kill them; they act like the antibiotics we use when we have a disease.
Stabilizers have a place, but ONLY if you store fuel, then they are necessary, if you bunker readily and constantly drain tanks of water then you do not need either of the above.However, because of the problems brought about from low Sulphur diesel, alternative, targeted additives should be used because some cash strapped suppliers add only the bare minimum
If your vessel is tied-up along-side for days or weeks at a time the fuel will degrade and may be susceptible to diesel bug. You should use a stabiliser that contains a biocide and drain the fuel tanks as regularly as possible. Life boats and emergency generators come under this heading.
If you bunker regularly in the Emission Controls Area’s (ECA), then a lubricity and deposit control additive should be used. Modern diesel in an ECA needs a lubricity additive which should be added by the supplier, most do, to a minimum, some don’t, so adding your own ensures the fuel system is protected. Additionally, modern diesel suffers greater system deposits so needs to have a detergent added, especially common rail engines.
If you operate and bunker regularly outside the ECA and are operating ‘standard’ diesel engines then I would suggest no additives are required.
The claims still persist however, during a recent exhibition I was presented with a product that would save 10% on fuel costs. Be clear fuel additives WILL NOT improve your fuel consumption, although the stabiliser MAY give a marginal saving due to the cetane improver. What they will do is prevent an increase in fuel consumption from fouled fuel systems and will certainly help prevent fuel system wear.
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Peter Weide is MD of MarShip UK, a UK based company specializing in optimising the efficiency of marine diesel engines. Advising on maintaining the cleanliness of Air, Fuel and Lubricating oil, we regularly recommend solutions to operators and appear regularly in industry press, with our full range of diesel additives DieselAid we can offer solutions for most operating conditions and wont advise them if you don’t need them.