The influences of different diesel/biodiesel blends and EGR rate on brake specific fuel consumption (BSFC), exhaust gas temperature, NO, HC, CO emissions, are studied and demonstrated. In this paper a four stroke direct injection, water cooled, diesel engine was used. Biodiesel either in neat form or as a blend with diesel fuel is extensively investigated to solve the twin problem of reduction of fossil fuels and ecological degradation. Exhaust gas recirculation (EGR) is an impressive technique for decreasing NO emissions. When EGR is utilized in engine, NO emission is decreased. If the engine was fueled with biodiesel-diesel blends, the BSFC would increase due to the lower brake power produced and It was found that BSFC increased with increase in EGR rates. Engine power and torque decreases through the use of biodiesel fuel blends. The results showed that B0 stands on the top level of power and B50 is at the lowest level. Reduction in exhaust gas temperature was observed but emissions of HC and CO were found to be increased with usage of EGR.
