The stricter worldwide emission legislation and growing demands for lower fuel consumption and CO2-emission require for significant efforts to improve combustion efficiency while satisfying the emission quality demands. Ethanol fuel combined with boosting on direct injection gasoline engines provides a particularly promising and, at the same time, a challenging approach.Brazil is one of the main Ethanol fuel markets with its E24 and E100 fuel availability, which covers a large volume of the national needs. Additionally, worldwide Ethanol availability is becoming more and more important, e.g., in North America and Europe.Considering the future flex-fuel engine market with growing potentials identified on downsized spark ignition engines, it becomes necessary to investigate the synergies and challenges of Ethanol boosted operation.Main topic of the present work focuses on the operation of Ethanol blends up to E100 at high loads up to 30 bar imep. Additionally, the ignition system behavior at these operation points and its requirements will be investigated. Analysis of the ethanol based combustion will be accompanied by thermodynamic analysis and correlations will be made with the ignition system analysis. The potentials and challenges of ethanol blend fueled combustion at high loads will be addressed in this work by measured data on an externally boosted single-cylinder direct injection SI research engine with manifolds and in-cylinder pressure indication for thermodynamic analysis.