ive done a little calculation wether converting to cng is feasable or not. before u read any furthur, i should tell u tht my maths is very weak, so if there are any mistakes, ignore em.
Consumption on fuel
13 km/L
cost of petrol Rs. 50
Daily usage 50 km (on avg)
Monthly expense on fuel= 50km x 30 days =1500km
1500km / 13=115.38 ltr
115.38 x 50= 5769 Rs.
Consumption on CNG
it would do 100+km in a Rs.200 gas fill (assumingly)=Rs.2/ 1 km
Monthly expense on CNG=1500km x2=3000Rs.
saving= 5769 - 3000= Rs. 2769/month
saving per year= 2769 x 12= Rs 33,552
so if some body travels 2000km+ a month, he will cover the cost of cng kit installation in 1 yr. Also there are no extra expenditures on a cng car, no need for early oil change & things like tht.