They occur about every 300 miles with my driving pattern which I believe is when the distance invoked regen occurs. 160-170 miles if doing regular journeys of 20+ minutes on motorways seems to frequent. How do you know they are happening at that frequency? Regeneration of the filter takes place automatically at an interval of approximately 300 – 900 km depending on driving conditions. Regeneration normally takes 10 – 20 minutes. It may take a little longer at a low average speed. Fuel consumption may increase slightly during regeneration. A forced DPF regen will make sure there is no soot buildup in the DPF / SCR System. Making sure to do this more than once could extend the life of your DPF system. We advise performing a service DPF regeneration once per month. Because your filters are clean and your exhaust is moving air more effectively, you might experience better MPG. How does DPF regeneration work? On Stage V engines, there are three types of DPF regeneration possible: In normal operation, the machine will perform a "passive" regeneration. Passive regeneration occurs automatically when engine temperatures are high and soot levels have increased. The system will try to run a regeneration process for 15 minutes. If unsuccessful, the system will repeat this process for a further 15 minutes, if still unsuccessful, the DPF light on the driver display panel will then be lit. You can monitor the soot level in the DPF with Vag-Com, here's how. Thermal Cleaning – Air cleaning is often not enough on its own, and heat is required to remove contaminants. This process involves heating the DPF to high temperatures (typically 500–600°C or 932–1,112°F) in a special oven device to evaporate and oxidize built-up soot and PM. Thermal cleaning typically takes about a day, including In some cases, the regeneration process may not occur or may be interrupted . by certain operating conditions such as low speed, prolonged idling and engine stop / start, etc. 1: PM (soot) threshold met. 2: DPF regeneration. 3: Clean DPF. If the process does not occur or is interrupted, the ECM is programmed to . recommence the regeneration The active regen normally starts at about 65% and you will not see any notice on the EVIC. It simply takes place in the background. The active regen will take place approx every 100-300 miles. The dealer can use their WiTech tool to force a regen even it the soot level is at 100% and the truck is in limp mode. DJH1.