A fuel burns more incompletely when less oxygen (O) participates in combustion than is required for the complete oxidation of carbon (C) to carbon dioxide (CO₂) and hydrogen (H) to water (H₂O). Among other things, this leads to the production of toxic carbon monoxide (CO).
The molecular structure of ordinary fuel is tightly bound. This means that the hydrocarbons (organic compounds of carbon and hydrogen) burn unevenly because the oxygen present cannot react optimally with the bundled hydrocarbon chains. This results in higher consumption, higher emissions, and lower performance.