The present work is focused on the production, emission and performance characteristics at variable compression ratios (CRs) on a compression ignition multi-fuel engine using Argemone Mexicana oil methyl ester and its blends with diesel (on a quantity basis) was observed and compared with the same. The feasibility of employing Argemone Mexicana oil methyl ester as a biofuel has been determined in the present work. Experiments have been conducted at a constant engine speed of 1,500 rpm and results are obtained at different CR of 14:1, 15:1, 16:1, 17:1, and 18:1. The ratios of blends used in this experiment are D100, AME5, AME10, AME20, AME35, AME50 and AME100, where the values relate to the share of the type of fuel given by the characters. The significance of compression ratio on the engine performance and emission has been investigated and presented for all the blends of biodiesel. The optimum results are obtained AME20 at CR17, which shows that the values of brake thermal efficiency, brake power, and specific fuel consumption are superior to that of both diesel and other blends. These blends, as fuel produces less emissions of CO, HC and marginally increase in NOx compared to that of diesel.