Many critical components in turbocharger are subjected to rapid temperature changes during operations. Thermal gradient within these components produces internal stresses and the repetition of these thermal cycles may cause a component to fail due to Thermal Mechanical Fatigue (TMF). Turbine Wheel, Turbine Housing and Manifold are subjected to TMF; these are the most expensive components of the turbocharger and have very complex geometric shapes. The maximum exhaust gas temperature could reach 1050°C. To assess TMF failure, it is very critical to accurately estimate metal temperature of these components subjected to complex duty cycles where exhaust gas temperatures vary significantly with time. Evaluating metal temperature and stress components from finite element analysis for complex duty cycles is a very time consuming process, particularly for complex geometries and approximately requires more than 3 weeks of time to complete analysis for different field complex duty cycles (driving conditions: city, highway and road). Several of these analysis cases are required to consider the impact of the real driving condition. In the present work we have developed an analytical methodology that is accurate and faster to predict the metal temperature and stresses in turbocharger components for complex duty cycles. This method was applied to evaluate the fatigue damage of turbine housing under actual condition.