The correlation between effectiveness and composition was investigated to choose the most effective pour depressant from the multitude on the market. Samples of pour depressants from the main manufacturers were collected and their ability to improve the low-temperature properties of diesel fuels was evaluated. The composition and structure of the additives with the best results and their solvents after separation by crystallization were investigated by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and chromatography-mass spectrometry. It was shown that copolymers of ethylene and vinyl acetate are the most effective pour depressant additives. Their solvents contain aromatic compounds.