I’ve read numerous threads on here and over on fullfat regarding this and unable to find a definitive answer. Think I’m starting to regret the purchase !
So picked the car up September and it was showing 9000 miles to service. Well that soon went down (despite not doing the miles) and was booked in for service 12th November on the 8th October 2000 miles still to service. 3 days later it suddenly needs an immediate service…… had only done 44 miles! Dealer was brilliant checked everything including the oil dilution which was high but not over the limit and gave the ok to continue use until service 4 weeks later, where they would investigate further.No charge and excellent service……
Service completed, and a clean bill of health issued on the 12th November…. Problem sorted…….

So Yesterday I noticed the service due was down to 4060 miles……… and we haven’t covered 2000 miles since the service. So I visited the dealers today.17 miles but this reduced the service indicator by 225 miles. There solution is 3-4 hours diagnostics at £216 an hour. The earliest they can see it 30th January……even though I pointed the way it’s going it’ll need a service in a week. Apparently it’ll be fine they also not really interested in checking the current oil dilution??
My conclusion is it’s either an intermittent fault, hence they haven’t any fault code for answers, or it’s dpf regen issue, which makes it unfit for purpose, or there is a mechanical fault that if not identified quickly will lead to a big hole in my wallet.
Welcome opinions, experiences or thoughts
Ta Jim

I have had a similar issue, I do my own servicing and reset the service indicator using my IId tool.
I did an oil change in late November, reset showed 13900 mls to next service,one month later and 1000mls it now shows 5900 mls to next service.
I have experienced this before, which is annoying and pointless, I keep a manual log of the mileage and change the oil every 5000 mls.
In the interim if I get the service due warning I reset it using the 'open bonnet, open drivers door, turn on ignition and press brake and accelerator fully for 10 secs'.
Hope this helps.

Thanks for the reply. Unfortunately imo not really a viable solution long term. The oil changes might still be in vain, especially if the dilution has reached the threshold for a change at 2500 miles? Plus my ocd couldn’t cope.
I went back to the dealer today, and had a grown up conversation with the service manager. Acknowledged there is an issue. His opinion is it’s constantly trying to regen ( wife’s commute 27 miles took 451miles off the service counter ) probably be an air leak causing overfueling. Thankfully hes found an earlier slot 14th January. I’ll update thread when I know more.

The problem with regen of the DPF is that you need to meet the threshold values for it to start and then continue. 27 miles of commuting might not get it in to "the zone" for it to regen to be carried out properly.

The manual method to regen the DPF is to get the engine to operating temperature (by driving it, not idling), then drive for 20 minutes at speeds between 45 -75mph (ideally, keep the speed between 60 and 75mph in Drive, using cruise control if possible). Then drive for a further 10 minutes. Plenty of commutes won't give that opportunity.

If the vehicle normally gets decent runs then active regens generally occur every 250 miles (according to the manual although this sounds quite low, doesn't it?), but if it's driven in urban conditions with light engine loads, active regen will happen more often. Sounds like yours is having this issue, especially if the regen doesn't complete and the ECU keeps commanding a regen (as was suggested to be the problem when this issued first raised its head a few years ago when DPFs became common fitments).

The oil dilution isn't measured directly, it's calculated based on driving style and regen cycles and the service interval adjusted accordingly. At 7% calculated oil dilution, the service message is shown. The software has been modified over the years (or at least the "service required" threshold has been raised) so you might benefit from a software update.

And one could always just take the beast out and give it a good thrashing up and down a favourite road now and then.  2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

I'm really interested in the outcome of this.
I said earlier that I have experienced the mileage to service reduction and if that is a bi-product of regen and over fueling, how come I get 36-37 miles to the gallon without really trying.
The car gets driven daily with mixed journeys around 30-40 miles.

We achieve, well the wife dose, similar mpg.
I think the overfueling wouldn’t have to be that excessive to increase soot levels. On my td5 defender, when the maf sensor fails, it becomes smoky. My understanding, and as mentioned above, the car calculates the regen is based on various sensors driving style algorithms etc, it’s not an exact science. The car bases oil dilution on these principles plus number of regens. So incorrect burning of fuel means its interpretation of the condition of the dpf isn’t necessarily correct, so let’s regen etc etc.
I also had a friend who’s v6 got permanently stuck in regen, caused by a fault in the plenum chamber.
Poor oil condition will ultimately prove very expensive

The book reckons regens add about 2% to the overall fuel consumption - a figure that's not going to be noticeable. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed