@Rajat Kumar Sinha, IMO the trick with MJD is to move quickly to 3rd gear and upwards. Accelerate just the right bit and not to exceed 90-100kmph on 5th gear; atleast for first few thousand kms. On a relatively straight lengthy road or highway, reset the trip meter (trip B) and drive in 5th with speed of 90-100kmph and recheck the FE at the end of the drive. You will get a good FE even now and in future at 80-100 kmph in overdrive. On upward inclines particularly those that cannot be managed in 3rd gear there will be obvious heavier fuel consumption giving you the FE you are now receiving; also if you cannot shift the gears just in time and quick enough. The engine should feel as stress-free as possible as quickly as possible.