My first post, been viewing this forum for about 2 months now, whiling digging up information on the car I wanted to buy. The forum helped me a lot as I learned a lot about gearboxes and various possible issues that could come up on an older car.

3 weeks ago, got rid of my bmw 320i and replaced it with a 09 plate audi a4 3.0 tdi tiptronic sline , it’s relatively high mileage with 87k but understand this these cars can go to 200k if looked after.

DPF Passive Regen:

I am using an Android app called VAG DPF (costs around 3) with an inexpensive odb2 Bluetooth adaptor to monitor the health of the DPF. It can tell you info such as soot loading, ash loading and dpf temperature while you are driving.

It was my understanding that the DPF would regen passively (temperatures between 350c and 500c) when driving on the motorway. Did a trip to Birmingham this weekend I monitored the DPF the entire way and noticed it did not passively regen at all on the way up. It did however perform an active regen (600-650c dpf temp) when the soot loading reached 25 grams on the way home.

Prior to the active regen I attempted to force a passive regen by driving in a lower gear 4th gear which has a rpm of 3000 at 70mph and 5th gear which has an rpm of about 2300 at 70mph. Also, tried driving in sport mode but for whatever reason the dpf temp never increased and occasionally reduced. The highest temp I managed to get it to was 320c and this was very briefly.

So, my question is has anyone noticed a passive regen occurring and what were the driving conditions at the time it occurred?

Thanks
Rakesh