Reposted as similar reply disappeared into the ether with an ‘error marking’ returned.
With my bu44ered hearing, I am perhaps not the best person to ask re engine noise. Although I can tell the X6 from a New Holland! I can also tell it apart from the similarly BMW engined Ineos Grenadier as that has much less sound absorption and has very different vehicle dynamics. Overall, the X6 40d is certainly no tractor and I wouldn’t describe it as ‘agricultural’ in any way.
Infact a few passengers have questioned whether the X6 40d was a petrol or diesel, so that might give you an indication.
As for dpf issues, my X6 was (and the new one will) be used as a sort of ‘Sunday best’ vehicle. I use the similarly engined Grenadier more on a day to day basis and for shorter runs.
I would say the X6 got a run out once per fortnight. Usually down to say Northallerton or Harrogate. (45/65 miles return trip) on a mix of country roads/A roads. The only time it did longer runs was when my brother in law borrowed it to tour Scotland, or my runs to/from Heathrow, maybe 3 or 4 times per year. I never had any dpf problems.
As I said, the Grenadier has almost the same BMW engine and gets used for shorter runs and very occasional long run (although currently being used for everything). Again, no dpf issues at all.