<p>A study was carried out on the rheological characteristics of water‑soluble high‑polarity base oils with an added polymer thickener and derived grease formulations. The parameters determining the key performance properties of these polyester systems were studied. It was found for these compositions that the yield stress and viscoplastic properties are primarily determined by the concentration of the thickener and its molar mass while the effect of temperature is insignificant. The structural strength of these lubricants was found to increase with increasing concentration of the thickener. A sample with optimal thickener concentration was developed exhibiting efficient energy dissipation and maximum yield stress. These findings can serve as a theoretical basis for optimizing the rheological properties of polyester lubricants such as thickened oils and greases for specific purposes.</p>