The calorific values of petrol and CNG are 45000 kj/kg and 50000 kj/kg, respectively. If you have vehicle which can run on petrol as well as CNG, which fuel will you prefer and why?
We will prefer CNG to run the vehicle. This is because the calorific value of CNG is higher than that of petrol. Therefore CNG will be more economical. At the same time it produces the least air pollutants. Thus, it causes less pollution than petrol.