Is that a Euro 5 or 6?
We have a Euro 5+ PVC with the 150 engine and it pulls like a train (after the first few thousand miles, during which it seemed gutless, but as it was run it in really came on song).
I normally trundle around in 6th at just over 2000 rpm, to ensure that DPF regens will complete as much as I can, but as I say it pulls like a train, very rarely have to change down on motorway trips - pulls quite happily up and over Shap summit on the M6 for example in 6th at around 60-65mph. And I get 32-36 mpg, quite happy.
If your van does mainly motorway driving it should passively clean the DPF on Euro5 and Euro6 engines, there should be no need for a forced regeneration unless lots of short trips are taken in the van where the DPF doesn't get hot enough to keep clean.