The problem of the military vehicles engines fuelling increases with the growth of the amount of vehicles in the armies. At the same time, another problem with fuel supply in modern engines is the use of bio component additives, which changes characteristics (quality) of the used fuels. Therefore, it is important to take actions to adapt engines to powering with fuels coming from renewable sources.The aim of the research was to evaluate the possibility of feeding the diesel engine (influence on the useful parameters and composi-tion) with mixtures of the unified battlefield fuel F-34/F-35 with biocomponents in the form of anhydrous ethyl alcohol and RME. The tests were conducted during fuelling of the engine with six kinds of fuels: basic fuel (diesel oil), NATO code F-34/F-35 fuel, as well as fuel mixtures: F-34 and RME with different ratio and F-34/F-35 with bioethanol. In the result of the research it was concluded that the parameters of the G9T Renault engine with the common rail fuel system in terms of F-34 and RME consumption (using) decreased in comparison to diesel oil basic fuel. It is not possible to supply the engine with the mixture of ethyl alcohol and F-34 fuel – alcohol pre-cipitation and obliteration of fuel system components