Can't say on behalf of others, but I am not saying that meter is wrong or something. Thing is mileage depends on many factors.. Even if you have empty road but you stop every 4 kms then your mileage going to suffer. If you travel signal free with minimum traffic within city than obviously it is as same as driving on highway. Even if you have difficult parking every time at work or at home, your mileage will suffer because there will be too much braking and power loss. Fuel quality, tire pressure, load in car to name the few other factors affecting car mileage, So that is why people get varying mileage with same spec car, even with same oil and miles on odo.
The best figures one can get is to compare his ride with his another ride with same driving habit, route, timings & load. I moved from new pkdm WR, it used to give me 14-14.5 km/l with 100% AC on same route after break-in time.
So, i came to know from your post that you own/ed 10th gen 1.6 corolla, how much it used to give you on similar driving condition as you run you cvti today ?