Sir Altis M/T cannot achieve more then 14km/l, no matter even if one uses 102 RON petrol or drive at 90km/hr dead steady.
No doubt Altis has the best engine and brakes (not braking) among all locally produced cars.
Altis suspensions are delibrately tuned soft so its ride is surely better at the expense of body control.
Else for a nearly 2M car, I do not want to comment on that, as a more then 2 decades old CB1 EX Accord is far more comfortable and stable on highway.
As far as meters are concerned they are never accurate, I have seen XLIs and Lancer doing 180km/hr on CNG and 1.8L Civics doing 240km/hr which is not even possible for a BMW 320i or Mazda RX8 RS.