The application of surfactants to reduce interfacial tension (IFT) on water/oil interfaces is a proven technique. The search for new surfactants is an ongoing research area, with applications in many different areas, such as drug delivery through nanoemulssions to enhanced oil recovery. In this work, we perform classical molecular dynamics simulations on combinations of cetyltrimethylammonium bromide (CTAB) and hyperbranched polyglycerols with one aliphatic chain (HPG), which were observed experimentally to lower the interfacial tension (IFT) of a water/oil interface by one order of magnitude, when compared to the individual surfactants. We were able to conclude that the IFT reduction effects come from a combined effect, mainly due to the CTAB-HPG strong interaction, weakening their interactions with the water and oil phases. The latter combined with an interface widening, less ordering, and spread of individual molecules' charge profiles, seems to lead to the much lower interfacial tension observed in the CTAB+HPG systems.