Nowadays, production of biodiesel from non-edible feedstock is gaining more attention than edible oil to replace diesel fuel. Thus, Ceiba pentandra is chosen as a potential biodiesel feedstock for the present investigations based on the availability in Indonesia and Malaysia. C pentandra methyl ester was prepared by two-step acid esterification (H2SO4) and base transesterification (NaOH) process. The purpose of this study is to examine the engine performance and emission characteristic of C pentandra biodiesel diesel blends in internal combustion. Besides, the detailed properties of C pentandra biodiesel, biodiesel diesel blends and diesel were measured and evaluated. After that, the biodiesel diesel blends (10%, 20%, 30% and 50%) were used to conduct engine performance and exhaust emission characteristic at different engine speeds. The experimental results showed that CPB10 blend give the best results on engine performance such as engine torque and power at 1900 rpm with full throttle condition. Besides, the brake specific fuel consumption at maximum torque (161 g/kW h) for CPB10 is higher about 22.98% relative to diesel fuel (198 g/kW h). This is shown that the lower biodiesel diesel blends ratio will increase the performance and reduce the fuel consumption. Moreover, the exhaust emissions showed that CO, HC and smoke opacity were reduced for all biodiesel diesel blends. However, NOx and CO2 were increased compared to petrol diesel. Overall, the results proved that C. pentandra biodiesel is a suitable alternative and substitute fuel to diesel. (C) 2013 Elsevier Ltd. All rights reserved.