well bro this model is not different than any 1.3 L car as far as the fuel average is concern..for better fuel economy city 2004-2008 is a good option..
Ur car has some low standard parts i.e cng switch, which doesnt show the exact consumption,i also have the same fake switch n same prob but ma consumption is ok alhamdolilah..
Bro u need to visit a technician who has a computer tuning option and can calculate the amount of carbon mono oxide through his computer and then adjust the mixture to get the emission at 10.6.
it helps in exact ideal mixture assessment instead of relying on USTAD GE's hearing abilities.
The other thing is that if u drive ur car on an altered air intake which is common for better cng pick then the car will definitely over consume once running on petrol due to non standard air fuel balance.
Try getting its THROTTLE BODY serviced and cleaned alongside new standard spark plugs adjusted to cng setting which is 0.5.
Get a genuine AIR FILTER it runs longer and the quality of product is good,min u should opt for a GUARD air filter
hope these suggestions help