Not only the electricity of 20 to 30 RS a day, we also need to consider the gas itself, and on top of everything, the cost of the actual unit too. We need to calculate how many years will it be before we can recover our invested money and start saving on the cost of the fuel. And then calculate the price rise in electricity, and gas for that calculated time too.
Also we need to consider if the actual car will last that long with the CNG quality flowing in our domestic pipes...
And finally, we need to see if we can infact recover the cost (let alone saving)before the unit requires a "renewal" as it says on the web page that it needs periodic renewal.
IF and IF the price of this unit (or the genuine unit) is really 2 Lakh ( i am unsure of the cost of this unit), then also calculate what you could earn with that 2 Lakh Rs in your posession, considering at least if we invested it in Qaumi Bachat scheme as this will be a loss on our side while this unit is consuming electric and gas bills!!! (just for example, consider that 2 lakh might give you 1500Rs a month. thats 50Rs a day which you could use towards buying CNG in the first place)
Well, personally, if I was doing 50 miles a day only, then I really doubt that after making all the calculations mentioned above, it will actually save me anything !!!!
Any more calculations guys?? 
