Just done Norwich to Birmingham, 166 miles, and got 48.7mpg.
A few caveats...
No AC for the majority of the trip (actually OFF, not just the compressor).
There were a few 40/50/70 average speed zones.
It was between 6-9pm on Saturday, so not too much traffic.
DPF/EGR etc done.
Millers additive in the tank (recommended).
Tyre pressures spot on.
Cruise control on for the majority of the trip, at at give or take, 75/80…
If you missed it, mine's a Q-Tronic
I don't thrash it often on a long run (that's for Norfolk's MANY B roads) but I don't exactly drive it like Miss Daisy either. Exiting dual carriageway roundabouts, services etc means a full on drag race
On the Norfolk B roads note, I usually get ~35 solely around town, and ~40 the B roads (they're just too inviting!!). Not great for a diesel, but I don't care. Some of my friends have VW/Audi's etc, and the way they go on about economy is depressing...
Is the 2.4 good for economy by modern diesel standards? No.
Is it more economical than a petrol? Yes (not getting into an argument about this).
Is it fun? Yes.