The use of CNG in automobiles has reduced pollution in our cities as it is a cleaner fuel as compared to other petroleum containing fuels. The Combustion of petroleum leaves unburnt carbon particles suspended in the air, along with carbon monoxide (CO) gas, which is harmful gas. Breathing CO causes a headache, dizziness, . But, Compressed Natural Gas (CNG) produces these harmful products in very less quantity. Therefore, the use of CNG has reduced pollution in our cities.