With soaring fuel prices, engine emissions, and demand for energy security, the development of alternative fuels from renewable resources has become significant. The current work explores the filtration performance of a commercial diesel filter operated with diesel blends of raw and processed karanja oils. Three processes viz. esterification, transesterification, and degumming were performed with karanja oil, and their diesel blends (20% v/v) were tested in a continuous run filtration system. The fuel filter plays a significant role in removing the contaminants/impurities from the fuel. Hence, the pressure difference across the fuel filter was monitored at the flow rates (0.03 m3/h and 0.075 m3/h) and fuel temperatures (30°C and 70°C). Besides, the effects of weight gain and surface morphology on the filter characteristics were observed during the study. Further, the head loss factors of fuel filter under varying operating conditions were deduced from the experimental measurements. The results of different processed oil blends were compared with fossil diesel to find the suitable blend. By considering the fossil diesel as the reference case, the average pressure difference for the degummed blends was significantly lower compared to other tested blends, which highlights the importance of the degumming process. Furthermore, the tested images of filter revealed the presence of minor components such as sludge or gums on the filter surface for the fuel without the degumming process. © 2020, Indian Academy of Sciences.