Abstract Dual Clutch Transmissions (DCT) for passenger cars are being developed by OEMs and suppliers. The driving force is the improvement in fuel economy available from manual transmissions together with the comfort of automatic transmissions. A dry clutch system (dDCT) is currently the subject of research, development, and production implementation. One of the key issues in the development of a dDCT is clutch durability. In dry clutches with current linings, above a critical temperature, the friction system starts to suffer permanent damage. In addition, the clutch friction characteristics are a function of the clutch interface temperature. Because a reliable, low-cost temperature sensor is not available for this application, the clutch control engineers rely on a good thermal model to estimate the temperature of the clutches. A thermal model was developed for dry dual clutch transmissions to predict operating temperature of both pressure and center plates during all maneuvers. The model is intended to be used to a) prevent clutch plate over-heating during abusive driving scenarios such as hill holding or multiple GCVW launches in both forward and reverse on grades and b) estimate clutch friction characteristics for control purposes. It is a Simulink based model that is integrated into the transmission controller to notify drivers and take corrective actions in case of overheating. The model also predicts the initial conditions for the temperature of the clutches during engine startups. The thermal model was validated fully in a test cell environment as well as in vehicles using slip ring and telemetry hardware. The thermal model has seven states that include both bell housing air and skin temperatures. Other parameters that affect cooling performance of a dry DCT, such as ambient temperature, and engine coolant and transmission oil temperatures, are also taken into consideration. Introduction Dual clutch transmissions (DCT) offer the full shift comfort of traditional step automatic transmissions but also combine the fuel efficiency advantages of manual transmissions. Because of their advantages, DCTs have attracted extensive development interests in the automotive industry in recent years. A general description of DCT development status can be found in recent publications [ 1, 2, 3]. Both wet clutch and dry clutch type DCTs have entered the automotive market recently. Wet clutches running in an oil bath or mist are used for higher torque applications where there is more energy to handle and more heat to dissipate. Their relatively high cost has until now limited their application to medium-sized vehicles with torque outputs of 250Nm or higher. Dry clutch design is generally suitable for smaller vehicle with lower torque outputs up to 250 Nm [ 4]. Dry clutch DCTs offer further improvement in fuel economy and option for modular gearbox families. Along with their advantages, dry DCTs have also raised some concerns, especially, clutch lining wear, thermal capacity and robustness against misuse. In dry clutches with current linings, above a critical temperature, the friction system starts to suffer permanent damage. In addition, the clutch friction characteristics are a function of the clutch interface temperature. Because a reliable, low-cost temperature sensor is not available for this application, the clutch control engineers rely on an accurate real-time thermal model to monitor the clutch temperature, use the clutch thermal state to estimate its torque capacity to increase the performance of the clutch system, and also provide driver warnings to prevent misuse of the clutch. Therefore, the clutch thermal model is a critical element of the transmission control system. In this paper, a seven-state thermal model, which assumes that a bell housing air temperature measurement is not available, is described. Some of the parameters of the clutch system which could not be meas