Palm oil biodiesel from both Tenera and Dura species of the oil palm was tested for performance evaluation in a techno single cylinder water cooled four stroke engine. Blends of the biodiesel with diesel were also tested and compared with the reference diesel fuel, (Automative gas oil). Torque measurement was carried out with a prong brake dynamometer and fuel consumption was measured by gravity with a 50 m1 burette and a stop watch. The engine was run at full load at a constant speed of 2000 rpm. Friction power was determined by Willan’s lines method. At peak loading, the engine had the highest mechanical efficiency of 85.97 percent at the brake mean effective pressure (Bmep) of 407.05kN/m2 with Dura biodiesel (B,100). It was followed by its blend with diesel (B110) with 76.32 percent at Bmep of 364.05 kN/m2. The third was the blend of Tenera biodiesel with diesel (B210) with 75.79 percent at Bmep of 364.05kN/m2. The fourth was the Tenera biodiesel (B2100) with 71.84 percent at Bmep of 381.44 kN/m2. The last was diesel with 67.61 percent at Bmep 381.44 kN/m2. Thus Dura biodiesel and its blend with diesel brought about enhanced mechanical efficiency in the engine, showing very good performance.