Watch out your driving behavior too, light foot vs heavy foot shows very significant different on this car.

How much RPM are u at during normal acceleration? better to keep it low like not more than 2k RPM and keep the eco light on most of the time as a guidelines too

Mine is MT, mostly getting 15km/l, mix highway and city 70% and 30% but no jam involved, I don't drive too slow too, mostly on fast lane 70%

I like the MT drive and its gear ratio setup, shorter 1-4th gear ratio compared to most similar car, made 4th gear quite powerful for hill climb and a rather ordinary 5th gear ratio setup setting the 4th and 5th gear slightly far apart, but u get an economical highway drive, but I hope it could be longer thou... 6 speed gearbox is a better solution to this anyway 

If you're with an Iriz, I would suggest you to keep the Iriz instead since the Persona wasn't a huge upgrade but just refinements from Iriz... not really worth thou