While changing the rear disks and pads (disks worn and scored) two nights ago, found that on the drivers side the brake cylinder was excrutiatingly stiff. A bit of TLC with ptfe oil, and now my MPG has become so much better.
Just done a (slow friday traffic) run from Havant to Oxford on the M27/M3/A34 route and AVERAGED 69.4 MPG.
I have never, ever, seen such mpg from the thing. Miles per tank has gone from 480-500 up to 590 for the last one (BP normal diesel).
Might try some premium stuff from BP or Shell to see what I can squeeze out of it.