Development of the Aerodynamics of the New Nissan Murano 2015-01-1542
The new Murano was developed with special emphasis on improving aerodynamics in order to achieve fuel economy superior to that of competitor models. This paper describes the measures developed to attain a drag coefficient (CD) that is overwhelmingly lower than that of other similar models. Special attention was paid to optimizing the rear end shape so as to minimize rear end drag, which contributes markedly to the CD of sport utility vehicles (SUVs). A lower grille shutter was adopted from the early stage of the development process. When open, the shutter allows sufficient inward airflow to ensure satisfactory engine cooling; when closed, the blocked airflow is actively directed upward over the body. The final rear end shape was tuned so as to obtain the maximum aerodynamic benefit from this airflow. In addition, a large front spoiler was adopted to suppress airflow toward the underbody as much as possible. This works to increase airflow toward the roof, thereby augmenting the pressure recovery on the roof, which reduces rear drag caused by wake flow. As a result of adopting these and other measures, the new Murano boasts the best CD of 0.31 among D-segment SUVs, while still maintaining high-quality styling.