I agree with the below comments, mpg isn't excellent with the 2.5, but if it's all about economy then you really should be looking at the 1.9's. My car has been remapped and I use mine both on motorway runs and sitting in loads of traffic in the morning on the way to work, so on average I see 32-34 mpg, but I do quite regulary see 47-48 mpg on a long motorway run. Awesome engines which sound great when you get the revs up, it only sounds like a diesel on tick over and very low revs.
Do check the history though, ideally you'd want to see short service intervals throughout it's life like I was lucky enough to find as the cams can wear on these engines quite easily if always serviced on long life intervals.
The timing belt and water pump with aux belts is another major thing you want to look for, at that mileage it should of not long been done, if it hasn't, walk away as that's a £700 bill! I've just had mine done and it's around a days labour to do, front end has to be removed to access the timing belt.
Another job I've just had done is the number 3 injector, it's not a 'common' fault on these engines but the specialist I use to service my car said he has seen it a few times over the years. I had an irratic idle where every now and then it would idle between 800 rpm (normal) and 1200 rpm, which made it sound like it was racing. It's to do with a sensor on top of the number 3 injector, unfortunately you can't just buy the sensor on it's own, it comes with the injector, and it's a total of £300 for the sensor and injector, it takes about an hour to change and then the injector has to be coded to the ecu and fuel pump, so in total it's about a £450 job.
Check the diff oil has been changed at regular intervals as well, it's quite normal to be able to hear the torque transferring to the rear diff on gear changes, but as your looking at an auto it may be different.
Hope those points help.
Arron
