Having now driven my NX some distance I have had to change my style of driving from that of the CT in order to help increase my MPG.
We all go through the settling in period where the sports mode button is fun but then reality kicks in and fuel economy is back on the cards.
I was advised by my dealer to get up to speed as quickly as possible, in his opinion this was the most economic way.
I have found that by leaving it in eco mode and steadily getting to the required speed whether that is 30,60 or 70 and leaving it in eco has produced the best mpg.
I am achieving 39/40 MPG by doing this and its not like Im travelling on a level road, A1, A66, M6/M74. this is my weekly commute at the moment so low fuel consumption is key.
I still have moments of madness where my lead foot returns but the majority of my route is at an acceptable MPG.
I hope this aids anyone hoping for better MPG, good luck