If your running truly is 12KM daily, do your self a favour and avoid CNG (certainly no good) like the plague. People here will keep on bragging about how good and economical CNG is, but there are many fringe benefits associated with it which you will only find out after your kit is installed. (no offense to CNG users). Getting back to topic, the City IDSI M/T is a very fuel efficient car, you definately wont need to install CNG in it. The car is very comfortable , but i cannot comment on Liana, as i have not ridden in it yet. best of luck for your car purchase, do post feedback here. AH