MID FE keeps getting more and more accurate with the distance being covered getting longer. If you are in a stop and go traffic or you are driving on highway with a stop every kilometer, the MID will be far from accurate.
On the other hand if your run is like say 200 kms continuous drive then there can be hardly 5-10% difference in what MID states and what you actually get. But yes, you need to drive in a consistent manner, too much changes in throttle inputs and Mr. MID is confused again. For an example, whenever my chauffy drives then I normally get equal or better than MID figure on both of my Polos but when I do then discrepancy increases till up to 10-15% at times.
On the other hand if your run is like say 200 kms continuous drive then there can be hardly 5-10% difference in what MID states and what you actually get. But yes, you need to drive in a consistent manner, too much changes in throttle inputs and Mr. MID is confused again. For an example, whenever my chauffy drives then I normally get equal or better than MID figure on both of my Polos but when I do then discrepancy increases till up to 10-15% at times.