An experimental investigation was conducted in a diesel engine to establish the effects of tetrahydrofuran (THF) with the Caulerpa racemosa algae methyl esters (CRAME) emulsion fuel. THF is added to the CRAME at different proportions such as 1% and 2%. The CRAME was produced from the Caulerpa racemosa algae oil by transesterification process. The aim of the present study was to analyze the experimental exploration of the antioxidants THF on engine emission of a diesel engine fueled with methyl ester of CRA oil. The test is conducted with different antioxidant concentrations of CRAME mixtures. The results exhibited that THF is effectual in controlling emissions.