Nexon petrol Mileage (1500km)

Nexon petrol mileage is a big issue in purchasing decision making process. I do had same in mind. I did purchase on sep23 2018. I have now completed 1300km. What I found that for first 200km, mileage was about below 10km ( mainly drove in city with lots of doped breaker). For next 500km it went up to 16km( mainly drove on highway with traffic jam at few places). Today I tried on NH and state highway with hardly any traffic issue... I kept Echo mode below 2k rpm in gear5. I was surprised to note mileage reached to 20.6km( yes petrol car..1st service due)....I hope I can improve further after first service..car is running well with little sound. Driving is comfortable specially person like me 6feeet tall. Did drive in Ahmedabad city traffic and found little late to respond specially in low Gera's.