The mileage of my 2008 civic. Got the car tuned and replaced all the filters when bought this year.
CNG: 100km city, 140km highway
Petrol: 9km/litre city, and surprisingly 16.5km/litre on highway (tested on the way to multan. Filled the tank from sahiwal, traveled 170km's and the fuel filled in multan was 10.25 litres. Driven on speeds between 90 and 110. Believe it or not. It is true.