The main objective of this article is to determine the true boiling point (TBP) curve of 08 crude oils (Campinas, Guaratinguetá, Leme, Pacaembu, Poá, Registro, Sales, and Sertãozinho – fantasy names – names of cities in the Sao Paulo State, Brazil) by high temperature gas chromatography, using the high temperature simulated distillation (SimDis-HT) analysis (ASTM D7169). Knowing the initial boiling point (IBP), it is possible to determine the loss of volatile components during the process. Accordingly, the distillation ranges showed different classes of oils, with Registro being the lightest, with 98.8 % recovery, followed by Sertãozinho (93.2 %) > Leme (90.6 %) > Guaratinguetá (89.7 %) > Poá (86.8 %) > Sales (84.1 %) > Pacaembu (74.8 %) > Campinas (57.1 %). Although Registro is considered the lightest oil (highest recovery), the oil that demonstrated the lowest IBP was Sertãozinho. Furthermore, Leme, Pacaembu, and Sertãozinho oils had their IBP around 40 ºC, and Guaratinguetá at 50 °C. Thus, these oils presented losses of light fractions at low temperatures (25 – 30 °C is the maximum temperature to avoid losses), limiting their processing in open and heated systems. Registro started to lose volatiles at 65 °C, and Campinas, Sales, and Poá at 75 to 80 °C. Therefore, these oils can be processed at higher temperatures (maximum of 60 °C), without suffering mischaracterization in open and heated systems. The distillation profile should not change after processing the oils, which means this analysis can provide important data to define the operating conditions of different types of processes (mainly in the primary treatment processes). Consequently, the SimDis-HT analysis can be considered as an efficient tool to find initial process parameters and to provide information for possible scale-up of processes with high temperatures and opened vessels.