Caption title. Includes bibliographical references.

Interest in fuels from renewable sources and their use in transport has grown over the last decade. This is because of their biodegradability, potential improvements in exhaust emissions and benefits on the virtuous COb2s cycle of the earth. Biodiesel fuels can be derived from rapeseed, sunflowers, and other kind of seeds or from UFO (Used Fried Oil). This paper analyses the results of experimental study fueling a Common Rail Diesel Engine with a 100% rapeseed Biofuel, with a blend of rapeseed and UFO biodiesel and compares it with commercial diesel fuel. Other papers by the same authors compared the different physico-chemical characteristics of biofuels, against diesel fuel and the consequent different spray characteristics that affect the combustion phenomenon. These characteristics are correlated with the different performances and emissions obtained in the experimental activity when a modern Common Rail light duty diesel engine is adopted. The addition of an electronic control of the injection process should optimize the results.