Five oil samples were considered in order to demonstrate the proposed approach. Information such as oil compositions and viscosity measurements were gathered from In order to apply the methods to estimate viscosities, a proper fluid characterization and lumping procedure is required. Due experimental limitations, the heavier components characterization procedure is necessary to circumvent the lack of information about properties of components heavier than heptane fractions, i.e., critical and saturation properties. Besides that, lumping is particularly mandatory to reduce the number of pseudo-fractions (up to C 200 with the adopted method for heavy oils) into fewer representative pseudo-components to avoid performance and phase equilibria convergence issues. We closely follow Pedersen et al. and related original research articles to estimate pseudo-components properties and to perform lumping on mixture components.