Here are some insights I've gathered from using the VAGDPF app to monitor DPF regeneration on my diesel Skoda Superb: Short Journeys: Frequent short trips result in poor fuel economy and quicker soot build-up in the DPF, causing regenerations to occur more frequently—sometimes as often as every 200 miles or even less if short trips dominate your driving pattern. Longer Journeys Help: Extended drives are beneficial. I’ve observed intervals of up to 370 miles between regenerations during consistent, longer journeys. Driving Behaviour During Regen: Maintaining a steady speed and throttle input during a regeneration seems to improve efficiency. Stop-start driving extends the regen duration, likely because the car adjusts DPF temperatures carefully to avoid overheating and reduce fire risk. Incomplete Soot Removal: Regenerations don’t appear to reduce soot levels to 0%. On motorway drives with steady speeds, the soot level typically drops to around 22% before the regen is marked as complete. In contrast, interrupted regens tend to stop at about 33%. Incomplete Regens Lead to More Frequent Cycles: If a regeneration is not allowed to complete, more soot remains in the filter, which shortens the interval before the next regen is triggered. This is a key reason why diesel engines aren't ideal for drivers who mostly do city or short-distance driving. Aggressive Driving: Hard acceleration or racing the engine increases soot production, meaning regenerations are needed more frequently. Fuel Additives: Based on my experience, I haven't noticed any measurable benefit from adding fuel additives to the tank in relation to DPF regeneration frequency or performance.