My Altis 1.6 is driven only 1600+ kms and it's average has increased from 11 to 12.5-13 kms/lit with full on AC, idling and being driven in congested bumber-to-bumper traffic all the time. I am sure it will improve further after i put fully synthetic oil on 5,000 kms.
The cherry on top is that there is no load felt with AC, while in case of 1.3 you do feel engine needing more power when you switch on AC.