Biodiesel fuel is covering more and more place in the market. The reason is a limited fossil fuels resources and the need to reduce emission of harmful substances by application of the fuel made of renewable resources. Currently in Poland and in Europe, the Fatty Acid Methyl Esters are used as biocomponent of the biodiesel fuel or it is used as pure biodiesel fuel. This paper presents the research on the biofuel, which contains mainly Fatty Acid Ethyl Esters, (the energetic value of FAEE is higher than FAME) and mineral Diesel fuel is a small addition. This paper presents research on the improvement of the compression ignition behaviour and combustion effectiveness of the second generation biofuel BIOXDIESEL, which contains up to 75% of biocomponents (FAEE with bioethanol) with addition of mineral Diesel fuel. Improvement of the auto-ignition properties is achieved through the multi-component composition of Bioxdiesel fuel and dosing of enriching additives. The quality of the fuel has been evaluated during engine testing and during laboratory measurement of fuel parameters. Whereas satisfactory results show that it is appropriate to supplement the composition of biofuels produced from waste vegetable and animal fats and alcohol with the refining additive.