Gasoline direct injection (GDI) engines have been developed rapidly in recent years, driven by stringent legislative requirements on vehicle fuel efficiency and emissions. However, one challenge facing GDI is the formation of particulate emissions, particularly with the presence of injector tip deposits. The Chinese market features some gasoline fuels that contain no detergent additives and are prone to deposit formation, which can affect engine performance and emissions. The use of detergent additives to mitigate the formation of injector deposits in a GDI engine was investigated in this study by testing a 1.5L turbocharged GDI engine available in the Chinese market. The engine was operated both on base gasoline and on gasoline dosed with detergent additives to evaluate the effect on injector deposit formation and engine performance and emissions. The injector fouling tests carried out in this study lasted 55 hours under the steady state engine condition of 2000 r/min and 3bar BMEP load. Injector flow rate loss, fuel consumption, gaseous pollutants (THC, NOx and CO) and particulate emissions were measured. It was determined that even a small amount of injector deposits may have a great effect on particulate emissions. The gasoline with detergents was proved to be effective in reducing the formation of injector deposits and particulate emissions.