What does the engine emit? (Opel Vectra B)

Carbon monoxide (CO) is perhaps the best known compound, as the CO content in the exhaust gases is measured in an idling engine. The richer the fuel-air mixture, the more of it is formed. A lean mixture, precise ignition timing and uniform distribution of the mixture in the combustion chamber allow for low levels of CO in the exhaust gases.

• Unburned hydrocarbons (HC) are formed when the flame front ignited by the spark plug is extinguished at the cold walls and in the narrow corners of the combustion chamber. The proportion of HC is mainly determined by the design of the engine; later it can only be slightly influenced.
• Nitrogen oxides (NC) are formed primarily due to nitrogen, which accounts for more than 3/4 of the combustion air. Their share is especially high in the case of an engine design with a minimum fuel consumption setting and minimum CO and HC emissions, high combustion temperatures and a lean fuel-air mixture.
• Sulfur dioxide (SO ₂) is formed only in diesel engines due to the sulfur content of diesel fuel.

What is dangerous and how dangerous?

• Carbon monoxide is poisonous and can be fatal if inhaled indoors. In the atmosphere, carbon monoxide combines relatively quickly with oxygen to form carbon dioxide (CO 2). It is not poisonous, but it significantly contributes to the "greenhouse effect".
• Hydrocarbon compounds are present in the form of a complex of compounds, with their palette extending from harmless to, in all likelihood, carcinogenic. In the atmosphere, hydrocarbon compounds with nitrogen oxides are responsible for the formation of smog (poorly soluble clouds of exhaust gases).
• O Nitrogen oxides at appropriate concentrations in the atmosphere cause irritation of the respiratory system.

"Acid rain"

The proportion of harmful substances in the atmosphere that are also responsible for the formation of acid rain is (data rounded to whole numbers):

(Text copied from a web portal: OPELBOOK)

• Sulfur compounds (SO ₂): 35% natural origin, 65% human activity, of which 97% power plants, industry and heating, 3% transport (diesel cars).
• Nitrogen oxides (NO_x): 95% natural origin, 5% result of human activity (half of them are for transport).

Tip: Around the world, the growing number of "burning spots" is releasing carbon dioxide. The reduction in forests and vegetation is not able to convert carbon dioxide into oxygen. The remainder is distributed in the atmosphere. In combination with other substances, it strengthens the opaque layer that reflects sunlight, experts determine climate change (greenhouse effect).