A Review of the Effects of Gasoline Detergent Additives on the Formation of Combustion Chamber Deposits of Gasoline Direct Injection Engines

Evaluating the effects of deposits formed in existing engines on their performance is essential, particularly for gasoline direct injection (GDI) engines, wherein such deposits can be even more problematic. Furthermore, it has been suggested that some gasoline detergent additives (GDAs) may increase combustion chamber deposit (CCD) formation. However, there is a lack of data available regarding CCD formation in GDI engines, and there are no systematic investigations of the effects of the relationship between detergent additives and CCD formation on the GDI engines operation. Thus, the aim of this article was to critically review the existing literature on the effects of the deposit buildup associated with GDAs on the knocking performance, emissions, and operational properties of GDI engines. Surveyed studies showed that, GDI engines produce higher amounts of CCDs compared with port fuel injection (PFI) engines. Moreover, the durability of GDI engines is adversely affected by injector deposits and CCDs as well as by engine preignition and knocking. A few studies suggest that these detergents accelerate the combustion-related formation of CCDs. Furthermore, the composition of the high-boiling-point components of fuels with high deposition tendencies has a significant effect on CCD formation in spark ignition engines. It has also been observed that there is a relationship between the amount of CCDs formed and the octane requirement increase. From a combustion viewpoint, the formation of CCDs should reduce hydrocarbon emissions because it increases the surface temperature.