Idle Re-Learn procedure
Fuel economy also depends on a lot of other factors too; your driving style, road / rush conditions, etc.
For a same car, same driving conditions, 02 different persons will get different fuel economy.
For a same car, different driving conditions, same person will get different fuel economy.
Try to drive with soft foot, do not give sudden acceleration / braking. Measure fuel economy from full fuel tank to full fuel tank basis, and calculate manually accordingly.
I hope, all above helps. Thank you.