22? What kind of derv car be that? Most will do double that.
You aint trying hard enough
Modern diesels aren't actually that economical until you can get them in a cruising situation. Which isn't always possible, or you are being a nuisance and getting in someone's way.
This will be STMO.......28 MPH in a 50 MPH zone so the motion doesn't make the whippet 'sick up' his Bonio.

This is how he gets 45 MPG.
I'm afraid I did a Jaime last week

Gave myself quite a shock

I was on the A6195 coming from the M1 towards Barnsley and some arsehole in a shitroen was up my arse, then passing, then slowing....you know the type, playing silly games.
Anyhow, I waited till the road was clear and put my foot down. Most cars will keep up with mine, but it's a question of bottle. He stayed close behind me for a while, then started dropping back. "C**t!" I thought, and glanced down at my speedo which was telling me 104mph. That is not clever on this particular dual carriageway as there are roundabouts at regular intervals.
When I got home I promised myself I would not do it again, let the daft bastards play their games.
I didn't have pooch with me, btw.