What is the difference between a fender and a wheel arch?
3 Answers
The difference between a fender and a wheel arch lies in their names, as they refer to the same component. The fender, also known as the wheel arch, is located on the outer body of the wheel. Its function is to reduce the drag coefficient based on fluid dynamics, making the vehicle more stable during driving. Depending on the installation position, it is divided into the front fender and the rear fender. The front fender is installed above the front wheel, which has a steering function, ensuring sufficient space for the front wheel's rotation. The fender designer uses the wheel travel diagram based on the selected tire model and size to verify the design dimensions of the fender. The rear fender does not have the issue of wheel rotation interference. For aerodynamic considerations, the rear fender is slightly arched and protrudes outward.
For DIY car modification enthusiasts, the terms "leaf fender" and "fender" actually refer to the same component. In early automobiles, the curved metal panel covering the wheel resembled a leaf shape, hence the name "leaf fender." Later, it was translated as "fender" from the English term, and this is now the commonly used term in repair shops. The front fender is installed above the wheel, extending from the headlight to the A-pillar, and is typically made of sheet metal or plastic. The rear fender, on the other hand, is a continuation of the body side panel and connects to the roof. The most obvious difference is that the front fender can be detached and replaced, while the rear fender is welded to the body as a single piece. If a fender gets scratched and needs replacement during repairs, it's usually the front one—buying the part online for around 200 yuan can solve the issue. However, if the rear fender gets dented, the entire panel must be cut and welded, making the repair cost at least three times more expensive.
Last time I helped a friend check out a used car, I noticed signs of putty repair on the left rear fender. Fenders are mainly divided into front wheel and rear wheel positions. The front fender is independently detachable, like those commonly fixed with screws in Japanese cars; while the rear fender is connected to the car body frame, making it a structural component. The most important thing to note is: if the rear fender has been in a collision, improper cutting and welding during repair can affect the body's rigidity. Damage to the front fender isn't as critical—the right front fender of my own car was dented by an electric scooter, and I just removed it, hammered it flat, repainted it, and it was good as new. Nowadays, some sports cars even use carbon fiber fenders to reduce weight, though the cost could buy you four regular car door panels.
