1. CNG reduces the harmful emission
2. Operating cost of the vehicle running on CNG is lower.
3. Reduced vehicle maintenance.
4. Fuel theft is not possible. Since NG cannot be siphoned off from a vehicle
5. CNG contains less carbon than any other fossil fuel.
6. CNG vehicle is as safe as petrol vehicle
7 CNG has a much higher Octane Number.—So, it is superior to petrol. And the anti- knock additives are not required.
8. Being a gaseous fuel, CNG mixes with air easily and evenly.
9. Almost any petrol / diesel vehicle can be converted to operate on CNG.
10. CNG is non-toxic.
11. CNG is lighter than air and so Dissipates into atmosphere implies less chance of fire Hazard.
Demerits:
1. Low engine performance.
2. Low engine volumetric efficiency.
3. Need of large pressurized fuel storage tank.
4. Refueling is a slow process
5. Inconsistent fuel properties.
So above merits and demerits suggest that CNG is used as alternative fuel.