On mine, average consumption according to MID instrument is a little bit higher than it actually uses.
I have noticed the fuel gauge not showing as you would think. It is more or less a logarithmic scale.
After filling up, it takes a long time before it shows any change.
If it shows 50% there is only about 1/3 remaining.
If it shows 1/4 the engine will fail when going up the next little hill.