Ethanol as an engine fuel emits less pollutants than gasoline, is a completely renewable product with good ecological implications, and has the potential to reduce greenhouse gas emissions. However, ethanol gasoline blends present a multitude of technical challenges to engine operation, including, the creation of adverse engine deposits, especially on inlet valves and injector tips. Special detergent dispersant additives in ethanol gasoline blends are the most effective way of bypassing these technical challenges. In the present work, two detergent dispersant additives, developed by the Oil and Gas Institute, National Research Institute, were used and investigated on a flex-fuel direct-injection vehicle with ethanol gasoline blend fuels containing 10 and 85% ethanol with special consideration of nanoparticle and non-legislated gaseous emissions. These researchers, among others, stated that, at cold start, particle count emissions are significantly reduced with ethanol blend fuels under all operating conditions. The detergent additives used in this investigation have no influence on gaseous and nanoparticle emissions.