The study presented here concerns the impact of car inclination on the temperatures in the vehicle underhood compartment. We report here underhood thermal measurements carried out on a vehicle in wind tunnel S4 of Saint-Cyr, France. The underhood is instrumented by 80 surface and air thermocouples. Measurements are carried out for three different thermal charges (thermal functioning points). During tests, the engine is in operation, and the front wheels positioned on the test facility equipped with rollers, permitting the wheel power and rotational speed control. Three car inclinations are tested.