Polystyrene, polybutadiene, polyisoprene, and their diblock copolymers can form high-pressure homogeneous solutions in propane that separate into two bulk phases upon depressurization. If the styrene block is large enough, the diblock copolymers can also form micellar solutions below the micellization pressure but above the cloud-point pressure. The onset of all micellization and cloud-point transitions can be realistically estimated within a Statistical Associating Fluid Theory (SAFT1) framework. SAFT1 parameters characteristic of the segment volumes and segment energies are found to be universally applicable to cloud points of homopolymers and diblock copolymers in propane. The onset of micelle formation can be predicted without readjusting the interaction energy between segments belonging to different blocks. This work is funded by NSF Grant CTS-0244388.