This article presents a new approach to validation of the methodology for determining the wear concentration of diesel elements in engine oil based on the adaptation of T2-Hotelling control charts. The advantage of this approach is the successful optimization of the methodology for determining wear elements in diesel fuel on the basis of statistical techniques. The purpose of the study is to substantiate the validation procedure of the newly developed methodology for determining the wear concentration of diesel elements in engine oil using the X-ray fluorescence method in the network of chemical and technical laboratories of Russian Railways OJSC in the context of a good approximation of the developed methodology. According to the developed methodology for determining the wear concentration of diesel elements in engine oil using the X-ray fluorescence method, the following elements were determined: Fe, Pb, Cu, Al, Sn, Cr and Si. The purpose of the study is to substantiate a statistical approach to the validation of determining the wear concentration of diesel elements in engine oil using a new X-ray fluorescence method based on T2-Hotelling control charts. T2-Hotelling control charts implemented in the Mathcad software environment allow tracking whether a particular sample has a systematic difference compared to samples considered under statistical control under the conditions of the developed new methodology. The scientific novelty lies in the adaptation of multivariate statistical quality control of measurements, which allows for the prompt implementation of the validation procedure in the plane of improving the quality of measurements. Practical significance. The results obtained allow monitoring the pre-failure state of the diesel engine by controlling negative changes in the physical and chemical properties of oils.