In order to reduce CO 2 , in many cases, CO 2 performance conflicts with power performance and comfort.We have to compromise between these requirements and produce a good solution. In early stages of vehicle development, the decisions for large-scale systems are important. Using a whole system simulation is effective for making these decisions.In this paper, we propose VHDL-AMS multi-domain simulation technique for the estimation of the vehicle performance at the concept planning stage. The VHDL-AMS is IEEE and IEC standardized language, which supports not only multi domain (physics) but also encryption. The common modeling language and encryption standard is indispensable for full vehicle simulation.By the HV Full Vehicle model, the fuel economy, the effect of heat energy recovery from the exhaust gas, and the power performance are discussed. The fuel economy was estimated using LA#4 driving pattern and the base simulation model validation result was that simulation was 22.0km/L and measurement was 21.7km/L (error 1.4%). The energy management using an exhaust gas heat exchange system realized 10.3% fuel consumption improvement during warming up. As for the power performance, the simulated acceleration time of 0-100km/h was 11.12sec and the measured vehicle time was 11.27sec. The error between simulation and actual measurement result was 1.4%.We showed that the application of VHDL-AMS multi-domain HV simulation is effective for the vehicle concept planning. Since the HV model uses embedded real control software, the VHDL-AMS modeling can be used as SIL at system control development stage.