Update: Filled up at garage yesterday, rest Trip B. Drove back home after checking tyres (38psi front and 36psi rear on 18" wheels), parked up at home.
Today I've been to Gordano services and back, from north east Brum, round trip of 199 miles, mostly motorway.
I kept to the speed limit, cruise control on at 70mph.
Rubbish traffic on the way back, had to detour along the M42 and M6.
The trip computer says 52.8mpg overall since reset yesterday. The gauge shows one and a half bars have been used, and 600+ miles on the trip A.
So not bad really!
And I know I'm sounding old and dull here, but it didn't actually take me much longer than the usual "motorway speed" driving i have previously done.
So the 1.9jtdm CAN be economical!