Diesel mpg - way of driving?

[HDi fun]

I've often thought that the onboard computers are slightly optimistic in their readings. The only true way to get a reading is to fill the tank to the very top. Record mileage at each complete refill and then dial in the numbers at the end of the exercise. Doing this with multiple fuel fills reduces errors. I suppose ideally the you should use the same pump at the same garage every time.

[chester]

On some eco driving guides it says to keep revs between 2000 and 3000 for eco driving.

I got 55mpg average before a remap and now 49-53mpg after. Only ever got 68mpg once and that was going 65 on the motorway just to see how high it would go. I need to get out more...