Fuel consumption

[runrabbitrun]

Hi all, i have a j11b 1.3 160bhp Qashqai and was hoping someone could explain the fuel consumption readings for me.
Firstly why are there two average readings ( 1 and 2 )
Also when i first got the car it was showing nearly fifty mpg on the dash but since i once reset it i can not get it to go above 41 mpg even though when i fill up and brim it i am getting 46mpg.
I know the computer is only a guide but cant understand why it won't go above 41.
Also when i turn the car off it comes up with current and best which don't seem to relate to anything.
And i have read the manual but it does not tell you much.
Have tried to upload photo's to show readings, hope it worked.
Thanks for any help.

[runrabbitrun]

Can't seem to upload 3rd photo which is when i turn car off, it shows current as 18 and best as 38.6.

[Slinn]

The dash display is a good estimate of your fuel consumption, but it might not be perfectly accurate. It's not uncommon for the dash reading to vary slightly from manual calculations based on actual fuel usage and distance traveled. The difference between the dash reading (41 mpg) and your manual calculation (46 mpg) could be attributed to such discrepancies.

[fbgqashqai]

Fuel economy 1 is the average reading of MPG since you last reset it, so if you reset this then drive and refill the vehicle with a reset again this is the avrage MPG for the tank of fuel used. Fuel Economy 2 is the avarge MPG obtained for the last journey and is automatically reset when you turn the ignition off.

[runrabbitrun]

Thanks for all replies, very much appreciated.