The main objective of the paper is to present the results of the CFD imulation of a DI single cylinder engine using diesel, biodiesel, or different ixture proportions of diesel and biodiesel and compare the results to a test ed measurement in the same functioning point. he engine used for verifying the results of the simulation is a single ylinder research engine from AVL with an open ECU, so that the injection imings and quantities can be controlled and analyzed. n Romania, until the year 2020 all the fuel stations are obliged to ave mixtures of at least 10% biodiesel in diesel [14]. The main advantages sing mixtures of biofuels in diesel are: the fact that biodiesel is not harmful o the environment; in order to use biodiesel in your engine no modifications re required; the price of biodiesel is smaller than diesel and also if we ompare biodiesel production to the classic petroleum based diesel roduction, it is more energy efficient; biodiesel assures more lubrication to he engine so the life of the engine is increased; biodiesel is a sustainable uel; using biodiesel helps maintain the environment and it keeps the people ore healthy [1-3].