This study evaluates the performance of an ethanol fueled spark ignited engine running with high levels of hydration. Ethanol is a renewable fuel and has been considered a promising alternative to counteract global warming and to reduce pollutant emissions. Its use is well established in ICE as the main fuel or blended with gasoline. However, due to its lower calorific value, it shows increased fuel consumption when compared to gasoline, rendering its use sometimes less attractive. The energy demand to produce ethanol, especially at the distillation phase, increases exponentially as the concentration of ethanol-in-water goes from 80% onwards. Thus, mixtures with less than 80% of ethanol-in-water would reduce the energy consumption during production, yielding a less expensive fuel. In previous studies, to evaluate the feasibility of wet ethanol as a fuel for spark-ignited engines, results have shown that it was possible to use mixtures of up to 40% of water-in-ethanol. This further experimental results aiming at optimizing combustion phasing for a fixed 50% mass fraction burnt point. The engine used in this research was a 4-stroke single cylinder 0.668L, originally Diesel fueled but converted to ethanol with a PFI system, an electronic controlled throttle body and a spark plug inside the swirl chamber. Tests have shown stable combustion despite the large water content. Emissions results have shown reduced NOx and higher CO for the higher water content ethanol.