The structural group composition of benzene and alcohol-benzene petroleum resins used as modifying agents has been studied. Benzene resins are characterized by a higher content of naphthenic and aromatic structures and a smaller content of aliphatic moieties. The introduction of resins into a petroleum wax solution in n-decane leads to the suppression of the crystallization of hydrocarbons (HCs) and contributes to a decrease in the structural, mechanical, and energy parameters of the system. The addition of benzene resins more effectively decreases the viscosity-temperature characteristics, i.e., leads to a substantial decrease in the viscosity, the activation energy for viscous flow, the specific energy of degradation of the disperse system, and the pour point.