Diesel cars and exhaust filters

  Diesel Cars

Adhering to the emissions standards for new cars means that almost all diesel vehicles are now fitted with a DPF. This is a technology which is designed to catch soot in the exhaust and as a result prevent it from entering the environment.

To keep everything running smoothly, the filter needs to be regularly emptied using a process known as regeneration. This is when the soot is burnt off at a high temperature, leaving just a small residue of ash. It’s a process that takes place automatically when driving at motorway speeds because the exhaust reaches a high enough temperature for the regeneration process to occur.

On the other hand, if a vehicle is mainly driven for shorter distances, at slower speeds, the cleaning process will not take place frequently enough to keep the filter clean. In these circumstances, most vehicles will initiate a forced regeneration by boosting the exhaust temperature to a point where regeneration will occur. However, this can mean that you need to keep driving for 10 minutes or so at speeds greater than 40mph until the process is complete and the warning light clears.

If the warning light is ignored, soot levels will continue to rise and the vehicle may enter a ‘restricted performance mode’ in order to limit any further damage. At this point, the vehicle will need professional attention to clean or even replace the DPF. This can easily cost upwards of £1,000 and is not covered by either your warranty or any maintenance agreement you may have with Total Fleet Services Ltd.

To protect your DPF and keep it running smoothly, it is important to follow the guidance found in your vehicle handbook and, if any warning lights come on, take the recommended action immediately.