Recently, there has been a growing interest regarding the synergistic combination of low salinity water with polymer flooding as a technique for enhanced oil recovery. Numerous studies have been conducted to investigate the efficiency of low salinity polymer (LSP) flooding in sandstone oil reservoirs; yet, there is no clear conclusion on the driving mechanism. Research lacks detailed explanation on the influence of brine chemistry, polymer characteristics, and rock mineralogy on the various aspects of crude oil/brine/rock (COBR) interactions. Consequently, the relative contribution of rock/fluid or fluid/fluid interactions to enhance oil recovery by LSP flooding is not well-understood. This study aims to scrutinize the main factors controlling the oil recovery during LSP flooding by performing a systematic experimental investigation of the interactions between crude oil, fluids and rock surface. Static and dynamic experimental measurements were conducted using artificial and native reservoirs systems (fluids and rocks) using brines of different chemistries. Rheological and fluid properties of the injected and produced fluids were measured to establish a baseline and quantify the main factors affecting the LSP flooding process. The impact of low salinity and polymer flood on oil recovery was assessed using synthetic brines and native reservoir core samples. The results revealed that the concentration of divalent cations and brine salinity significantly influenced the electro-kinetic properties of the crude oil/brine and rock/brine interfaces in the presence of polymer. The rock/brine interface became less negatively charged with decreasing concentrations of divalent cations and brine salinity, while the oil/brine interface became more negatively charged under the same conditions. Furthermore, reducing the concentration of divalent cations or the salinity of the make-up brine showed a significant impact on the viscoelasticity of polymer solutions but did not affect pH or the interfacial tension (IFT). In addition, the presence of polymer in the brine was found to affect ion exchange reactions, equilibration processes, and extending the stabilization time during flooding experiments. Polymer molecules led to an increased concentration of divalent cations in the effluent, which was more pronounced with decreasing brine salinity. Additionally, it highlighted the greater influence of anion exchange reactions on pH of the effluent compared to cation exchange. Moreover, LSP flooding showed better viscosity recovery, which can be attributed to the relative change in cation and anion exchange reactions. LSP led to high presence of sulfate ions in the effluent. The sulfate ions act as bridges between divalent cations, preventing strong interactions with the polymer chains and maintaining viscosity stability. The ratio of monovalent to divalent cations was identified as a major factor influencing oil recovery by LSP flooding, regardless of rock mineralogy and injection sequence mode, while pH and mineral dissolution had a minor effect. The viscoelasticity of the crude oil/brine interface, influenced by factors such as oil viscosity and total acid number (TAN), was found to be a crucial determinant of the success of LSP flooding. These results have broad application and significance in LSP flooding for heavy oils to design LSP injection strategies that yield improved oil recovery from sandstones reservoirs.