The practical use of biofuels is a very controversial, complex and ambiguous issue. Biofuels are considered to be a means of getting rid of many problems. It has gained this reputation due to the lack of attention paid to the complex processes of production of biofuels and raw materials from which it is produced, as well as the great difficulties that arise in its use. Unfortunately, little attention is paid to the fact that different types of biofuels are completely different in terms of their impact on cars, engines, fuel equipment and not all meet the requirements for them when working in the agro-industrial complex. In fact, it is already clear that the daily unregulated use of biofuels will lead to numerous failures of diesel engines and huge repair costs. Each family of biofuels is produced using different technologies. Despite this, work in this direction is being actively pursued, there are still no standards for various types of biofuels, as well as for the raw materials used, production and technological processes and environmental standards. In practice, this may mean that different biofuel producers will sell under the same name fuels with very different physical and chemical characteristics, not to mention that they contain potentially hazardous substances. In addition, its effect on engine mechanics, whether biofuel in a mixture with conventional or pure biofuel, whatever it may be, has not been sufficiently studied. Biofuel itself can be a strong solvent and gradually clog the injectors with dissolved substances. Biofuels made from ethanol can be hygroscopic, and the moisture dissolved in them affects the corrosion of engine parts. Components of such fuels can also adversely affect engine gaskets and seals, as well as fuel supply systems made from organic materials. Simply put, there is a clear incompatibility between the materials of modern diesel engines and biofuels when used in high concentrations.