Before investing tons of money in installation and maintaining CNG in your car, first make a simple decision. Is it worth it??
1- Most of people drive less than or equal to 30KM per day (A good tuned car on petrol gives easily 13-16) and 30KM means Rs.200 petrol.
5 days a week means 1000 weekly and 4000 Monthly.
2- On CNG mostly people get around 120~170 in 8KG Cng. Which is around Rs.650. And for around 30KM Drive this will work for whole week. Monthly expense will be 2600.
So, there is difference of around 1400 Per Month and to save this amount you have to wait in long CNG lines as well. Also CNG vehicle gives more trouble (due to additional parts) and I think every month or two you have to visit to mechanic. But on petrol people hardly go to mechanic for maintenance not more than twice a year.
I recommend to all PW members to take some time when they are waiting in CNG lines and do the calculations for themselves. Most of the people will agree to remove CNG from their vehicles.
Here in Islamabad, for me it was around 1000 rupees difference monthly and I opted to remove CNG.
But when I was in Karachi, my daily running was around 60KM and in Karachi it was making sense to keep my CNG in place because monthly difference was around 3000 rupees.