The consciousness of deteriorating fossil fuels and the adverse impact of its consumption on human health have diverted the research towards alternate energy sources. Biodiesel seems to be the best promising alternate fuel for diesel engines as it has potential to partially or completely eliminate diesel from compression ignition (CI) engine. Several investigations on performance and emissions had shown that use of double biofuels (biodiesel-oil blends) have ability to completely replace diesel. But, the lubricating properties of fuel also affect the performance of engine as some engine parts are lubricated by the fuel itself. In the present study, effects of concentration of biodiesel in blend, temperature and load on friction and wear are investigated with the help of four ball tester. As biodiesel is subjected to oxidation and has highly affected lubricity at higher temperature and load, so the effect of oxidation was also studied. The operating loads and temperatures were 147-392 N and 45-60-75 degrees C respectively. During operation of four ball wear monitor, frictional torque was recorded with the help of data acquisition system. The scars on the balls are investigated with the help of microscope. An analytical ferrography was also done to analyze the wear debris in the used oil after each test. It was found out from the present investigation that the operating parameters collectively affect the lubricity. (C) 2017 Elsevier Ltd. All rights reserved.