The petrol engine powers most of our motor vehicles. The burning of fuel in the cylinder after ignition by the spark is sudden and intense. The temperature soars about 2800 Celcius and some nitrogen and oxygen in the cylinder combine to form nitrogen oxide. As the piston is pushed of the cylinder, the combustion gases expand and cool in less than a hundredth of a second. The heating-cooling cycle occurs so rapidly that much of the fuel is not completely oxidized to carbon dioxide and water. Some carbon monoxide is formed and some hydrocarbons remains unburned.
To be continued