New season…New fuel?

As we look forward to the new season and begin the usual preparations, this is an ideal time to perhaps consider the new EC Directive applicable to Ultra Low Sulphur Diesel (USLD) fuel which came into effect from 1st January 2011 and how it will affect us boat owners.

The Directive sets the environmental specifications to be applied to fuels for road vehicles and non-road mobile machinery (including inland waterway vessels when not at sea), agricultural and forestry tractors, and recreational craft when not at sea.  The standards refer to the sulphur content of gas oils intended for use by non-road mobile machinery and states that it must not exceed 10 milligrams per kilogram of fuel, meaning its virtually ‘sulphur free’.

While these regulations relate to inland shipping vessels and recreational craft operating on inland waterways, regulations for sea-going vessels are not changing.  These can still use the exsiting fuel, which contains 1000mg/kg of fuel.

The reduction of sulphur in itself will not harm existing engines, although some may find that they require an additive to make up for the loss of the lubricating effect.  However, this new fuel may contain up to 7% of a certain bio fuel, obtained from renewable sources known as FAME (Fatty Acid Methyl Ester).

So whilst the purpose of bio fuel is to reduce emissions, making it more environmentally friendly, there are factors to be considered, some of which can have potentially serious effects on engines, namely:-

  • This new fuel has higher water content which encourages more fuel bug type growth in the tanks.  This causes problems with blocked filters.
  • The chemical breakdown in the fuel to acids leads to engine equipment damage and leakage – mainly with the fuel hoses and seals.
  • Storage life of bio fuel is reduced – expected life is around six to twelve months in the fuel tank.
  • Cost of changing pipes and filters to accommodate bio fuel.
  • Cost of possible wastage, cleaning the tanks, and regular filter changes due to leakage and blockage.

Generally it is advisable for boat owners to only ask for non bio low sulphur fuel to encourage stockists to only supply this type of fuel.  As the supply chain is varied, the following advice should be considered going forward:-

  • Remove all water from the tank and filter/water traps.
  • Change fuel filters more frequently.
  • Turn the fuel around quicker.
  • Check for signs of fuel leaks during the season.
  • Fit a high quality fue/water separator and drain regularly.

The fuel system on older engines is much more likely to have issues as most modern leading engine manufacturers comply with the latest emission regulations and are designed to run on sulphur fuels.  If in doubt you could check for identification on the engine itself.


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