Fuel oil is one of the important parts to support daily activities. The demand for fuel oil is increasing every year. Therefore, the search for the latest energy source is continuously conducted. Carica papaya L. seed oil is investigated as a renewable energy source replacement part of petroleum diesel fuel. C. papaya seed oil obtained through the extraction process using soxhlet method with n-hexane solvent. Then produce methylester by means of transesterification using 1 % NaOH catalyst and 20 % methanol of the weight of the oil and stirred at 400 rpm for 1 h. A mixture consisting of 10 % C. papaya seed biodiesel and 90 % petroleum diesel fuel, called CPSB-10, produces fuel properties that meet the specified standards by the Indonesian Directorate General of Oil and Gas. From the result of the performance test in a diesel test engine, the maximum brake power and brake thermal are consecutively 30.6 kW and 140.23 N m, the lowest sfc is 268 g kW–1 h–1, and the highest brake thermal efficiency is 32 %.
