Effect of Multifunctional Fuel Additives on Octane Number Requirement of Internal Combustion Engines

Multifunctional fuel additives prevent the formation of deposits in the entire Intake System of Spark Ignited engines (carburetor, injection jets, intake valves). However, fuel containing these additives can produce additional deposits in the Combustion Chambers. This can result in a higher Octane Requirement Increase (ORI) than can be obtained for the same engine running on the additized fuel.

The authors have investigated the influence of additive formulations and of individual components of additive systems on ORI. The changes in Octane Number Requirement are followed by determining the onset of knocking in a Mercedes Benz M102E engine fitted with pressure sensors in the cylinder heads.