The fuel heating system has completed a decade of operation in flex fuel vehicles to enable engine start in cold start conditions. Besides its proven-in-use benefits to reliable engine start, some recent studies have shown advantages of heating fuel also with respect to emission reduction, drivability enhancement and fuel economy. These benefits make this system a potential candidate to meet the increasingly demanding requirements of the new Brazilian emission legislation PROCONVE L7/L8. To allow system operation, not only to cold starts but whenever required, it is necessary to evaluate the system behavior under different use cases to determine the new system’s mission profile. Therefore, a multitude of tests is required to collect this data for analysis. However, performing such tests with the actual system can be very costly and time-consuming, due to the high variance of test parameters, such as engine sizes, fuel blends, emission driving cycles, ambient temperature, etc. The objective is then to replace part of the physical systems by models that allow more flexible and cost-effective tests. With representative models of the engine and the engine control unit (ECU), it is possible to command the fuel heating hardware from a PC in a controlled laboratory environment and acquire the relevant data. This work presents the benefits and challenges from applying the simulation tools and models to define the system requirements and deepen knowledge of the cause-effect relationships in order to optimize further product development process.