In the current work, the effect of using CPO (crude palm oil)-OD (ordinary diesel) blends as fuel on the performance of Cl (compression ignition) engine is studied. Three different blends of CPO-OD (25%, 50% and 75%) were investigated using direct-injection, stationary diesel engine. The CPO-OD blends were preheated to about 60 degrees C before the injection to reduce the viscosity of the blends. The experiments were conducted at variable engine speeds (1000 rpm through 3000 rpm) under fixed throttle opening. The results revealed that the CPO-OD exhibited higher torque and power output at engine speeds lower than 2000 rpm, while the BSFC (brake specific fuel consumption) was found to be higher than the OD at the same engine speeds. CPO enhanced the BSFC at higher engine speeds (above 2000 rpm). The CPO-OD blends exhibited lower emissions of NO and higher emission of CO compared to the OD. (C) 2011 Elsevier Ltd. All rights reserved.