The vehicle used engine Automobile exhaust is the most problematic substances out of the car, namely. Carbon monoxide, hydrocarbons, oxides of nitrogen And sulfur Then, about 55% of the hydrocarbons coming out the exhaust pipe from 25% out of the crankshaft and the other 20% is due to the volatility in the carburetor. And fuel tanks Oxides of nitrogen Nitric oxide (NO), nitrogen dioxide (NO2) and nitrous oxide (N2O), almost all coming from the exhaust. It is directly toxic to humans In addition, lead in gasoline to increase the amount of lead in the air, super well.