DPF - no doubt again

[eddie_delaine826]

I have searched for DPFs and added somewhat to what I was already aware of, but I still have a couple of unanswered questions as to how best to minimise any problems after following my very recent purchase of a 3.0 diesel.

I understand that:
- Diesels like long journeys;
- It's best to use premium fuel (some may disagree);
- They are expensive to sort out if they get clogged up;
- The more time the car spends running at full temperature the less particulates will be produced for the DPF to 'mop up', and of course, vice versa;
- Checking the oil level on a regular basis is a good idea not only to see if it's low, but also to see if it's raised as a result of uncompleted regeneration cycles;
- stopping the car during a DPF regeneration cycle before it is completed is a bad idea.

My car will do a fair amount of short journeys (which for a diesel seems to mean anything less than a 30 minute run in mostly free-running road conditions) and longer journeys (50 to 150 miles about every 4-6 weeks). The car has done 69,000 miles over 11 years with its previous owner , with the annual mileage having reduced progressively from 10k/year to approx 2000 last year and 3000 the year before that; I don't know the make up of those miles, but suspect that recently there were more shorter journeys than longer ones. There are no messages on the dash at present.

What I'm not clear about is:
- Will the DPF be cleared on every longer journey, or do the particulates simply build up less quickly until the DPF does require a regeneration cycle?
- Is any message put up on the dash when a regeneration cycle starts, or is the only sign to spot the excess smoke from the exhaust?
- Once you've detected (by whatever means) that a regen cycle has started, how would you know that it has completed?
- Is it inevitable that the DPF will eventually fill up/get clogged at some point and if so does it make sense to get a proprietary process of fully cleaning it done before the DPF FULL message comes up?
- The owner's manual talks about running for 20 minutes after the car has warmed up at 30 mph for a regen cycle; I have seen opinions that are more like running for 30 minutes at a minimum of 2500 revs, which would be way over 30 mph but could be done at maybe 50mph in a lower gear. Is the manual versin adequate and/or does the 2500 revs apply if/when the warning messges come up?

Any enlightenment on these points would be greatly appreciated - thanks.