Group 1 - The article discusses the importance of reducing energy consumption in automobiles, highlighting the trend of using aerodynamic features such as diffusers to achieve this goal [1] - A diffuser is described as an aerodynamic component located at the rear underside of a vehicle, primarily found in performance and supercars, which helps to increase downforce by managing airflow [1][2] - The article explains that diffusers do not directly generate downforce but rather accelerate airflow beneath the vehicle, creating a low-pressure area that enhances stability at high speeds [2][3] Group 2 - The mechanism of how a diffuser generates downforce is detailed, explaining that as air flows through the vehicle's underbody, it accelerates due to the shape of the diffuser, resulting in a pressure differential [2] - The article clarifies common misconceptions about diffusers, stating that they act more like a pump to speed up airflow rather than producing downforce themselves [3] - An example of innovative design is provided with BMW's Vision Driving Experience VDX concept car, which features multiple fans and motors to actively create downforce, achieving significant lateral acceleration [3]