but only comes when I do the MFA reset by holding the button and turning power on, off then on again.
Is that not operating the 'secret' menue?
Yep, nothing comes up otherwise.
When I'm travelling and I scroll through the MFA, Only the things I listed work (clock, oil temp, ambient temp) and everything else comes up as a couple of dashes.
Only get a figure on the others when I get the 'secret' menu, and thats insane, hence the 219mpg!