Abstract: The invention relates to a method for producing a stable boron solution with lubricating characteristics which is intended to be used preferably as an addition in the form of a concentrate/additive to a liquid, e.g. to a liquid fuel or a lubricant. The invention is achieved by the method steps of using a boron substance of pharmaceutical quality (1, 11), using a liquid as solvent, applying a mixing ratio between the boron substance and the solvent (3, 13) of preferably 1 g of boron per 15-25 litres of liquid, agitating the mixture for an initial predetermined period of time (4, 14), adding further liquid to dilute the solution (6, 15), the quantity of liquid being chosen such that a fmal user mixture reaches a concentration of between 20 and 30 ppm of boron (8), and further agitating the mixture (7, 16) for a second predetermined period of time so that the boron substance is completely dissolved in the boron solution, resulting in a boron solution which is stable over time.