Defined by their solubility class, asphaltenes represent the most polar, aromatic, and heaviest fraction of crude oil. They strongly adsorb at oil-water interfaces, forming viscoelastic films that confer solid-like mechanical properties that stabilize crude oil emulsions. It is suggested that asphaltenes form the most stable crude oil emulsions close to the onset point of precipitation, in which soluble and insoluble asphaltene nanoaggregates are in solution. The formation of these emulsions leads to undesired flow assurance problems for the oil and gas industry that require demulsification to prevent operational challenges and costs. Given the heterogeneity in chemical composition, structure, and molecular weight of natural asphaltenes, it remains challenging to identify how their aggregation, precipitation, and diffusion behavior at oil-water interfaces promote stability. We use small-angle X-ray scattering (SAXS) and the oscillating pendant drop method to address this challenge and investigate the structure, aggregation behavior, and the dilatational rheology of asphaltenes and asphaltene-model molecule violanthrone-79 (VO-79) with decreasing solvent quality. We observed that the radius of gyration (Rg) is independent of solvent quality before the onset point of precipitation and decreases as solvent quality decreases. In addition, our results show that the complex dilatational modulus of soluble asphaltene nanoaggregates depends on the solvent quality and increases with aging. On the contrary, the interfacial dilatational response of VO-79 remains relatively constant with increasing aging and decreasing solvent quality. We hypothesize that soluble asphaltene nanoaggregates may be re-arranging at the oil-water interface due to their dispersed nature, thus influencing their packing and enhancing the mechanical proper- ties of the asphaltene-stabilized interfacial film, thereby promoting emulsion stability. The direct connection between structure and the dilatational response of oil-water interfaces stabilized by soluble asphaltenes is essential for understanding their interfacial properties and their role in the emulsification process near the onset point of precipitation. Understanding the relationship between the structural and interfacial features of soluble asphaltenes provides insights into developing effective demulsification strategies to prevent flow assurance issues associated with asphaltene-stabilized crude oil emulsions. Additionally, this work demonstrates feasibility in emulsion-based industrial applications.