The influence of operating parameters on the performance of spark ignition engine has attracted the interest of engine manufacturers and researchers. In this instance, selection of optimum criteria of operating parameters based on experimental results is expressed as a multi attribute decision making (MADM) problem. In this study, a mathematical model which is an integration of Analytic hierarchy process (AHP) and Weighted Euclidean distance based approach (WED) is proposed to select optimal combination of operating parameters. The parameters chosen are compression ratio (6,7,8,9), fuel blends (E10, E20, E30, E40) and load (25%, 50%, 75%, 100%). Consistency check of weights of attributes was carried out by AHP and the weighted distance of attributes from the most and least favorable situations was evaluated using WED. Optimum criteria with the combination of compression ratio of 8, fuel blend of E20 at load of 100% was found to be optimum. The results of proposed mathematical model were compared with another MCDM tool, Graph theory matrix approach. The proposed model allows the decision maker to analyze and evaluate the weights of attributes logically and systematically to make decision.