dc.description.abstract | Population growth and the use of transportation have led to increased use of fuel, especially for petroleum products, so it is necessary to develop and switch to renewable energy. One reliable renewable energy is biodiesel. Rubber cultivation produces rubber seeds that can be reprocessed into fuel because of their oil content of 45.63%. In addition, High Density Polyethylene (HDPE) plastic garbage, namely gallon cap, is also one of the materials that has the potential to be processed and used as an alternative energy source by the pyrolysis process. This study aims to analyze the performance of stationary TD-115 diesel engine using a mixture of biodiesel fuel from rubber seeds (RSB) with plastic pyrolysis oil (PPO) with the ratio 100% pure diesel, 60% diesel + 40% RSB, 60% diesel + 30% RSB + 10% PPO, 60% diesel + 20% RSB + 20% PPO, 60% diesel + 10% RSB + 30% PPO. The engine operates at a rotation of 2200 rpm with a weight of 1500 g, 2500 g, 3500 g, and 4500 g, respectively. The results show that torque, power, and thermal efficiency decrease compared to pure solar as the percentage of rubber seed biodiesel increases, on the contrary, specific fuel consumption (SFC) and exhaust gas emissions increase. The best fuel blends performance relative to pure diesel is solar 60% + RSB 10% + PPO 30 %. where the average reduction in torque and power is 4.3%, thermal efficiency is 2.15%, CO content is 40%, HC is 30.5%, Opacity is 25.5%. Also, SFC increased 15.6% | en_US |