Different types of diesel additives
EN590 describes the standards for the physical properties that diesel must have. These standards allow the incorporation of 7% of biodiesel, and soon this percentage is expected to increase by 10%.
Today, diesel fuel with 7% biofuel complies with the EN590 standard, and the diesel fuel with a higher percentage cannot be sold at petrol stations until the regulation changes.
Biodiesel is a renewable natural resource, which makes vehicles more environmentally friendly. This type of fuel generates fewer emissions than diesel and is used to increase the lubricity of low-sulphur diesel because its lubricating properties are very high. However, biodiesel has some disadvantages…
Disadvantages of biodiesel:
- Poor cold flow properties
- Poor combustion
- It’s more prone to oxidation and acid formation
- Contains more water than regular diesel
- May affect fuel system seals differently to standard diesel
- Because it’s composed of natural resources, it is more sensitive to biological decomposition
This is why using additives helps stabilise the fuel, improving cold flow properties, corrosion protection, water dispersion and clean deposits so that efficient fuel is generated.
Over the years, the sulphur content, one of the fuel’s natural lubricants, has been reduced and this has led to increased wear on fuel pumps and injectors, which now operate at high pressure and tight tolerances.
Additives that treat the fuel system must take all these factors into account. Cleaning additives must also provide lubrication and, when servicing the system and changing the filter, it is essential to re-prime it when installed, as air ingress can also cause damage.
The fuel filter is designed to remove particles from fuel before they enter the high-pressure system. Quality fuel filters will filter particles down to 2 microns, which will greatly reduce particulate input.
By adding fuel to the tank or from a container directly to the filter, this fuel can bypass the filtration process and these larger deposits can be introduced directly into the pump and injectors.
Some additives can also be used to prevent the growth of bacteria in the fuel. When diesel fuel is allowed to sit and moisture is absorbed into it, a microorganism known as Diesel Bug can grow in the fuel tank. This bacterial growth can cause the filter to clog and lead to vehicle failure.
Another use of the additives is to prevent fuel breakdown and the formation of fatty acids in colder temperatures. These are created by the percentage of biodiesel in standard fuel, and at low temperatures (around -11 degrees) can thicken and form sludge, reducing fuel flow and blocking the filter, which prevents vehicle operation.