Thanks for all your feedback guys, its really useful.
As an update, Ive just been on a trip down to Cornwall for the week, and the car has returned the following - Motorway journey, non stop from Merseyside to Peranporth, a miserable 42 MPG. That was at a steady cruise controlled 65 mph too. It averaged 35 pottering around Cornwall, and then returned a miserable 39.5 MPG on the return home today. again non stop at 65 - 70 Mph! Not impressive figures for an oil burner!
The hesitation is still there, and hasn't improved with the run (so bang goes my theory of a blocked particulate filter!), but it is still totally unpredictable and I even detected some hesitation in third which I've not felt previously?
The next step has to be an AA or RAC engineers report unless anyone thinks its worth putting it on a dyno to see where the drop off occurs??
Still frustrated...!!
