This paper presents ail evaluation of thermal comfort in ail extended road trial study. Automobile seats play an important role in improving the thermal comfort. In the assessment of thermal comfort in autos, in general subjective and objective measurements are used. Testing on the road is very difficult but real traffic conditions affect the comfort level directly, as well as the driver's experience to real conditions. Thus, for such cases real traffic situations should not be neglected in the evaluation of comfort. The aim of this study was to carry out, on an extended road trial study, ail evaluation of thermal comfort using human subjects. In the experiments used, the 100% polyester seat cover had three different cover materials, which were velvet, jacquard and micro fiber. All experiments were carried Out on a sunny day with tell participants over I h. They were carried out at air temperatures of 25 degrees C in a Fiat Marea 2004, which had an automatic climate function. Skin temperature at eight points and skill wettedness at two points on the human body were measured during the trials. Participants were required to complete a questionnaire of 15 questions, every 5 min.