Thanks for your reply mate.
129000 miles.
I've only owned the van 3 months. I probably do about 10 - 15 miles per day. Each journey would be about 4 miles. I do the often long run of 40 miles once a week to make sure dpf is getting up to temp.
Dpf has just been regenerated by merc and it's apparently in good condition.
I use shell diesel optimax which is supposed to be the cleanest diesel available in my area.
Trying to find how to pm a moderator!!!! Thanks again.