Coalescence is widely studied in surfactant solutions. Nevertheless, a prediction of the lifetimes of liquid films between bubbles is still lacking due to intricate couplings between flow and concentration fields, and disjoining pressure effects associated to surfactants. As a consequence, the situation for surfactant solutions is so complex that predicting the lifetime of a liquid film with surfactants is a challenge. We identified a very simple system in which describing quantitatively the stability of films is possible. These are liquid mixtures, such as oil mixtures, miscible in all proportions. First, the disjoining pressure is always attractive and independent of variations in composition. Second, surface/volume transfers are only controlled by diffusion with no adsorption delays. Third, interface elastcity can be varied by orders of magnitude by changing the volume fraction. Lastly, they exhibit a very low pollution sensitivity, due to their low surface energy. Consequently, the question of coalescence, and its consequences on diphasic flows, is well posed in these systems. We will describe the physical mechanisms acting to stabilize single suspended liquid films made of binary mixtures in a specially designed cell by measuring their lifetime. These experiments will be analyzed and compared to numerical simulations to improve our understanding of the stabilizing mechanisms in oil foams.