Bro!
There must be something wrong, too much idling on AC ON or more active or aggressive biased driving habit other wise the city 1.3 and 1.5 Manual gives the same consumption in city i.e. 12 -14km/L in city AC ON / OFF included without excessive idling and highway 15 to 19 km/L depending upon your driving style. This doesnt include hypermiling....It is with normal driving style.
I kept 2012 city and drove it 94000km with nobody ever seated on driving seat conservatively except myself......
You are giving data of 1.5 and 1.3 Auto tranes correctly. i.e. 8 to 10 km/L city and 10 to 13km/L highway.
If somebody is going for City.....Its best to go for 1.5 MT or Auto ....eyes closed keeping in view my experience with 1.3 City(Although it is very nice trouble free and lighter than a GLI / Xli and more fun to drive).
and go for the only Tyre up size i.e. 195/ 60R-15.....MAJORITY IS GOING FOR 65 which makes a lot of bouncing effect and alters ride quality and out of stock tyre upgrade limit 2.5% as per tyre upsize calculators.