Driving it to France in a week, so will see how it performs. I reckon I should be able to do around 750-800 miles out of the 10 gallon tank anyway, if I sit at 60.
Suppose I should update this, as I returned this afternoon.
I managed to do 68mpg on the first tank - I got from Runcorn, just outside Liverpool to Folkestone, over to Calais (although the train did that bit) and down to Brugge on less than half a tank! A total of 385 miles, excluding the chunnel. In total from that tank I did Runcorn-Folkestone-Brugge-Folkestone-Milton Keynes, which is 632 miles out of 8.2 gallons, give or take. The trip computer is not exactly known for being spot on, so I've taken it with a pinch of salt. I did hit 70 at various points on the way down, used the air con etc. Surprising how much fuel the air con uses, to be honest!
Either way, 68mpg is pretty good taking that into consideration.
This is the map of how far I managed on a tank, either way.
I filled up in MK and sat behind the lorries on the way back up the M1/M6/M56 and managed to hit 95mpg (!). I did 155 miles from MK to home on just under a gallon and a half
:smiley: Not bad on fuel, these Mk4 Clio diesels...