A high concentration of palm oil biodiesel fuel blend is a strong candidate to substitute conventional diesel fuel (B10) due to its prospect to release fewer emissions. This paper shall present findings when testing palm oil biodiesel fuel blends (B10, B20, and B30) at medium speed (2500 rpm) in a single-cylinder Yanmar L70N diesel engine coupled to an eddy current dynamometer. In this study, a timed burette and an airbox determined the engine’s fuel and air consumption, respectively. In contrast, a flue gas analyzer measured the emission released by the fuel blend. The result indicates that as the concentration of palm oil biodiesel increases in the blends (from B10 to B30), there is no significant difference (average less than 5%) between the fuel blends in terms of brake thermal efficiency, brake specific fuel consumption, and air-fuel ratio. On the other hand, the emission results showed a reduction in CO, CO2, and NOx when the concentration of palm oil biodiesel increases in the blends. Considering the fuel blend would have no significant difference in the engine performance and its ability to reduce most emission, it is safe to conclude that B30 would be a good alternative for current diesel fuel (B10).