Petrol is used in a car engine is it useful and harmful?

Petrol is used in a car engine is it useful and harmful?
Petrol is known also as gasoline. It is useful because it makes the car run. But it is harmful to the environment due to the byproducts of the combustion required to make it run the car. The exhaust of a car that uses gasoline has many poisonous gasses and compounds. Carbon monoxide is one. This gas can kill you easily, even in your own car while you are driving it down the road.