Mujtaba, it is very simple to calculate the CNG kit cost recovered, as i have already mentioned that around 10k to 15k is saving each month on CNG as compared to petrol, lets take
my monthly mileage is 2000KM
if i drove on pertol, it will cost Rs.16,800 per month. the stats which i applied is "Petrol price: Rs.101/Ltr -Mileage: 12KM/Ltr - Per KM: Rs.8.4"
if i drove on CNG, it will cost Rs.4,600 per month. the stats which i applied is "CNG price: Rs.61.64/KG - Per KM: Rs.2.3"
Net Saving per month: Rs.12,200/-
CNG Kit Cost: Rs.50,000
Cost recovered period: 4 Months
@sk_king: you can get the spacers from Dora shocks wala at saddar rawalpindi, it will cost Rs.1,500/- and your car will lift upto the original position, never experienced any problem even on bumpy roads.