Results of a research project aimed at studying the capability to develop a method (economic and simple) for on-board biodiesel blending detection are described. The method is based on the direct measurement of the Indicated Mean Effective Pressure (IMEP). The study was carried out on a 2.0L four-cylinder "torque-controlled" Euro 5 diesel engine for passenger car (PC) application. This engine, equipped with instrumented glow plug for combustion closed-loop control, represents the state of the art of the diesel engine control technology. Two biodiesels were chosen for the experiments: a rapeseed methyl-ester (RME) and an aged RME, while the conventional diesel fuel was an European (EU) certification diesel fuel. Results indicate generally a good response in blending detection of the method. However, in order to attain an acceptable accuracy, a pre-calibration appears necessary. (c) 2011 Elsevier Ltd. All rights reserved.