
The performance and emission characteristic tests have been carried out on a single cylinder direct injection diesel engine running under constant speed and variable loads. In the first part, the engine tests have been conducted with used cooking oil methyl ester (B100) and their blends with conventional diesel oil in the proportions of 20:80 (B20), 40:60 (B40), 60:40 (B60), and 80:20 (B80). In the second part, the engine tests have been conducted with blends of conventional diesel oil, used cooking oil methyl ester (UCOME), and diethyl ether in the proportions of 76:20:4 (BD20), 52:40:8 (BD40), 28:60:12(BD60), 4: 80:16 (BD80) and 0:83.33:16.67(BD100). A series of tests have been conducted for each of test fuel. The engine is allowed to run at constant speed at 1500RPM, but at different loads (0.4, 4, 6, 8 and 10kg). The performance and emission characteristics of blends are analyzed and compared with conventional diesel oil. The experimental results obtained for UCOME are comparable with conventional diesel oil with the increase in engine performance and reduction in engine exhaust emissions.