Pollutants released by automobiles?

Question

what is the percentage of pollutants released into the air by automobiles? Do you think introduction of CNG in some cities has been helpful in reducing pollution levels?

Answer 1

every little bit helps

Answer 2

the amount of pollution released by automobiles has been substantially reduced over the years. in fact current automobiles put out less than 5% of what cars of the 60's and 70's put out pollution wise on average. credit electronic fuel injection, modern materials, updated engine efficiency, and modern emission controls for the changes. and yes the introduction of the use of CNG has done some good. however it is a mere drop in the ocean since the number of CNG powered vehicles is extremely small, but growing in some places. understand however that CNG is still a hydrocarbon based fuel, that while burning cleaner than gasoline, still has its issues.

Answer 3

Yes, one factor that contributes to air and noise pollution.