Nowadays, different countries use ethanol as a self-propulsion fuel. However, this biofuel is aggressive for metal parts in the fuel system of an automobile. In this study, we determined the corrosion rate of duralumin, a material used in the production of piston engines, in ethanol-gasoline blends at concentrations of 5 to 20%, through electrochemical impedance spectroscopy (EIS), Tafel polarization and Gravimetry. It was shown that the corrosion process control was mixed with a tendency towards localized corrosion. It is generally observed that the corrosion rate of duralumin decreases during the exposure time.