All diesel vehicles produced after 2006 will include a diesel particulate filter (DPF) in the exhaust assembly.
DPFs are a service item, and require replacement once they are full of ash.
Doug Bentley, research and development manager at Klarius Products Ltd explained that fuel borne catalysts (FBCs/Eolys) aid the DPF regeneration process by lowering the required temperature for soot to burn inside the device.
He said: “FBCs contain a solution of metal compounds, which after the combustion process, adds metal oxide particles to the soot that enters the DPF.
“These metal oxides serve as a catalyst inside the DPF, allowing soot to be burned off at a temperature of 250 – 300°C, which is far lower than that required otherwise.
“This allows for a wider range of regeneration over differing engine modes, which increases the service life of the DPF as more soot can be burned off more of the time.”
FBC fluid is typically stored in a separate tank, which usually requires refilling every 60,000 miles or so.
This fuel additive system is widely utilised by OEM manufacturers such as Peugeot, Citroen, BMW Mini, Ford, Volvo, Mazda, Volkswagen, Skoda and Lancia. Some FBC brands are OEM specified, allowing drivers to select the optimum FBC fluid to increase the performance of their DPF.
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Diesel exhaust fluid (DEF/AdBlue) reduces the nitric oxide and nitrogen dioxide (NOx) levels emitted from the diesel exhaust gas stream into the atmosphere.
The system was introduced as a direct response to more stringent EU legislation on NOx emissions, gases that cause wide ranging damage to the atmosphere and local environment.
This is achieved via the injection of DEF into the exhaust gases after they have passed through the DPF, then reacting the fluid inside a selective catalytic reduction (SCR) Catalyst to create cleaner emissions.
Doug said: “DEF is a clear liquid which should contain 67.5 per cent demineralised water and 32.5 per cent pharmaceutical grade Urea.
“This mixture reacts with NOx inside the SCR Catalyst to produce less harmful nitrogen, water and carbon dioxide.
“The process generally requires a combined CAT/DPF unit or separate catalyst – increasing the complexity of the exhaust assembly.
“Typically a vehicle will consume a litre of DEF fluid every 500 miles, so the tank will require filling at regular intervals to ensure vehicle performance is maintained.”
DPF cleaning fluid
Klairus say DPF cleaning fluid is usually only utilised when a replacement DPF is unavailable, and requires the ash counter to be reset once the process has been completed and the DPF reattached to the vehicle.
Other such products include fuel tank additives, which are mixed directly into the fuel tank with fuel.
Doug said: “Many aim to reduce the carbon build up on sensors or clean catalytic converters.
“However, more unsubstantiated claims are made by inferior products, so potential purchasers are advised to be wary when assessing the credibility of a product before entering it into the fuel system.
“Claims such as ten per cent increases in fuel economy or increases in horsepower sound too good to be true.
“DEF and FBC fluid systems allow diesel vehicles to further reduce emissions and improve air quality.
“Such is their importance, that many exhaust assemblies are tailored in their design to incorporate the benefits of these fluids.
Related: MOT changes to be introduced in May following DPF investigation
“While more established fluid systems undoubtedly improve the performance of the DPF and reduce emissions, many more unproven products on the market offer a potential pitfall for purchasers.
“Therefore it is vital to specify quality fluids that are supported by either an OEM or highly credible aftermarket source to avoid potential damage to a vehicle,” Doug concluded
Klarius has announced that it is to launch its own range of additives in the near future.
For more information on Klarius, click the ‘more details’ link below.