This paper presents a scientific and practical study of the problem of selecting the model mass for aerodynamic testing of scaled vehicle models using a small-scale aerodynamic testing facility. The research was conducted at the aerodynamic laboratory of Andijan State Technical Institute and involved 3D-printed models of hatchback, sedan, and minivan type vehicles. The relevance of the study is explained by the fact that relying solely on geometric scaling is insufficient for laboratory investigations of vehicle aerodynamics, while the model mass has a significant impact on measurement accuracy. At the initial stage of the research, the model mass was determined according to the n³ scaling law; however, noticeable measurement errors and reduced stability of results were observed for some models. Therefore, additional experiments were carried out using different model masses, and the obtained experimental data were analyzed using statistical processing methods. As a result, an empirical relationship between the real vehicle mass and the test model mass was established, providing the most stable and reliable aerodynamic measurements. The findings of this study contribute to improving the methodology for selecting model mass in small-scale aerodynamic testing facilities and enable a reduction in measurement errors in vehicle aerodynamics research