On my old 2.5TD LWB, used to get around the same 25-28mpg.
Didnt believe everyone who told me I would get the same out of my now 3.5GDi! Last tank, I averaged around 29.4mpg, which was a mix of motorway, round town and 'booting' it!
2.5s are very prone to cooling problems. They have the balance belt fitted too, so that needs to be kept 100%, otherwise it DOES snap and it tends to take the timing belt with it....... and so on! I loved my 2.5, but did have to replace the head on it. Although the least powerful of the range, some dont 'enjoy' towing, mine was very capable both off and on road.
The 2.8s dont know much about them really, although I know the timing chain is prone, as are the pump seal, and the latter being a very expensive repair bill. Although these are neglible in power difference to the 2.5, they are happier towing.
On that basis, didnt discard the petrol versions. The 3.0 is a very good engine, the 3.5 24v MPi is a beast of a plant, yet the 3500 24v GDi is both a beast and a pussycat, with a 'tiptronic' J-gate box, which is a dream.
Same with any car really, look around, there are loads still out there, although some are starting to get tired now. M/N-plate or newer I would recommend. BUT, and its a BIG BUT. Remember, it will feel the right motor when YOU sit in it and it puts a smile on yer face knowing this is the one.
Again, with all vehicles, hunt round, dig deep, and you will not regret the swap!
Just my opinion, hope it helps!
