Driven by increasingly stringent tailpipe CO2 and fuel economy regulations, gasoline direct injection (GDI) engines are enjoying rapidly increasing market penetration. Already more than 50% of newly produced vehicles in the US and western Europe feature direct-injection technology and markets in Asia are catching up quickly. However, with the adoption of this new GDI engine technology, which is able to push the boundaries of engine efficiency, new challenges are starting to arise such deposits which can adversely affect performance. Multi-hole solenoid actuated fuel injectors are particular vulnerable to deposits left by some market fuels. In order to address this challenge, the development of a reliable test platform for injector cleanliness in GDI engines is currently underway in both the US and Europe. This study shows the successful application of a direct injection bench engine test platform to differentiate different fuel formulations at a high statistical confidence level based on an engine metric correlated to injector cleanliness. Robust statistical design and operational experience are two levers that make it possible to avoid the use of artificially pro-fouling dirty-up fuel formulations to accelerate deposit generation. In this study a European (EN228 compliant) market representative test fuel is used throughout the entire investigation. The study makes two cross-comparisons between three different fuel formulations and the bench engine deployed is shown to be a highly sensitive test platform to differentiate fuels with different levels of deposit control additive. Fuels formulated with appropriate deposit control additives have been shown to help to maintain injectors in factory original operational status and moreover restore injector performance in cases where deposits were formed.