What is the inner frame of the fender also called?

[JadeLynn]

The fender, also known as the wing panel, is the outer body panel that covers the wheel. Based on the installation position, it is divided into the front fender and the rear fender. Its function is to utilize fluid dynamics to reduce the drag coefficient, making the vehicle drive more smoothly. Additional information is as follows: 1. Function: By leveraging fluid dynamics, it reduces the drag coefficient, ensuring a smoother drive. During the driving process, it prevents gravel kicked up by the wheels from splashing onto the bottom of the cabin. 2. Principle: Since the front wheels have a steering function, it is essential to ensure the maximum limit space for the front wheels during operation. Therefore, designers use the "wheel envelope diagram" based on the selected tire model size to verify the design dimensions of the fender. The rear fender does not have the issue of wheel operation interference, but for aerodynamic considerations, the rear fender is slightly arched outward.