With the rise in fossil fuel consumption rate, depletion in reserves and stringent pollution norms resulted in search of renewable and carbon neutral fuel. Ethanol is one such fuel that can be obtained from various feedstock’s including grains and green matter with high starch and sugar content such as corn, sugar cane and sugar beets. Even castor oil methyl esters which is non-edible in nature also fulfils the requirement of fuel for internal combustion engine. The traditional experimental scheme requires more time for optimization and extensive experiments need to perform as it is possible to vary only one parameter at a time. This also result in increase in cost and it doesn’t provide interactive effect among the chosen variables. Mathematical models of Taguchi method using design of experiments (DOE) provide good results. By using DOE, Taguchi L27 orthogonal array is considered. Analysis of variance (ANOVA), Regression Equation and signal-to-noise (S/ N) ratio are obtained to predict the optimal parameters and to evaluate the influence of significant conditions on performance, emission and combustion characteristics. It is observed from the experiments that ethanol blend percentage and EGR influences on the output parameters.