Lignin is a high-energy-content material, which could be used as feedstock for future transportation fuels. To this aim, it must be liquefied and upgraded. Currently, the most promising way of upgrading is considered to be hydrodeoxygenation. By combining an upgrading reaction pathway network and a model of a spark ignition internal combustion engine, the fuel properties are linked to the degree of upgrading. This study answers the question how much upgrading is required to obtain the optimum fuel for a spark ignition engine. Depending on the optimization criteria (efficiency, specific CO2 emissions, or volumetric fuel consumption), different selections of compounds are identified both for summer and all-year applications. Most of the compounds exhibit a significantly higher efficiency than gasoline at lower volumetric fuel consumption. Specific CO2 emissions are expected to be marginally reduced, compared to gasoline. Furthermore, this study confirms that the initial bio-oil is not suitable as fuel and reveals that complete hydrodeoxygenation is not beneficial.