Gas injection processes are among the most effective methods for enhanced oil recovery. A key parameter in the design of a gas injection project is the minimum miscibility pressure (MMP), the pressure at which the local displacement efficiency approaches 100%. From an experimental point of view, the MMP is routinely determined by slim tube displacements. However, because such experiments are very expensive (time-consuming), the question we want to answer in this article is as follows: Is this still necessary to measure the MMP? In other words, may other quicker, easier and cheaper gas injection experiments such as swelling test or multicontact test (MCT) substitute for slim tube test? This paper concludes that when the injected gas is not pure CO2 (and probably not pure N-2 or pure H2S), it is enough to fit only two parameters of the equation of state on data including classical PVT data + swelling data + MCT data and then to predict the MMP. The accuracy obtained is similar to the experimental uncertainty. It is thus possible to conclude that the slim tube test may be replaced by swelling tests and MCT, which are much cheaper.