CO is formed when there is insufficient O2 to completely oxidise the fuel during combustion of fuel. The amount of CO formed in a diesel engine is considerably lower than a petrol engine because of supply of continuous excess air to the engine. Theoretically, diesel engine should not emit CO at all as it always operates with excess air. However, CO is present in small quantities in diesel exhaust and this is, possibly, due to the fact that the fuel injected during later part of injection does not find sufficient O2 as a result of local depletion in certain parts of the combustion chamber.
The percentage of CO in exhaust varies from 0.1%−0.75%, which is easily acceptable level.
Leave a Reply