I have 1.6. I have observed that its meter shows great mileage for initial 20 km after it is reset and the roads are empty and you have a steady drive in high gears for 20 kms it will show you up to 19 kms, but as soon as you enter a congested area the average falls to 15 and when you have driven more than 80-100 kms, the average stay between 11-12 (all time ac and local).
Most of the time my meter shows 11 to 12 kms so this is the average of my Altis 1.6 AT in city in too much congestion.