Fahad bhai, ghussa janay dain i agree k khuaari bohot hy but there still is a lot of difference.
lets take 1 unit of both.
1kg gas = 80rs (new rate)
my car does around 22km EASILY in 1kg gas
so that turns out to be approx. 3.5rs/km
Now, 1 unit of petrol.
1ltr petrol = 107rs (new rate)
a good avg is 14km/ltr local
that turns out to be 7.6rs/km
difference per km = 4.1rs
for a guy like me who drives 4-5k kms a month, this is a saving of 16400-20500 PKR per month which means an annual saving of 196800-246,000 PKR.
Now that is quite a good amount
even if u decrease the mileage per unit of cng and increase that of petrol, the difference is still huge...
and here the part that everyones gonna find really interesting... its about my own car. it has mileage of 2,25,000kms now. first 19600kms was done on petrol.
Distance covered on CNG = 2,05,400kms
total saving = total distance covered x saving per km
total saving = 205400 x 4.1
total saving = 8,42,140 PKR
which EXACTLY was the cost of the car back in 2006
and the difference of 4.1rs per km is not avg. the difference was much higher back in 2006-2008 when price of CNG was around 34-43rs per kg and petrol was near 80rs/ltr (1:2) so if i account for that avg too,the saving is 1 million PKR plus howz that