What is the name of the black plastic half-arc above the tire?

[McOwen]

The black plastic half-arc above the tire is called the wheel arch trim. It refers to the chrome-plated bright strip along the upper edge of the tire, which is a semi-circular component protruding from the fender above the car tire. It consists of 1/2 steel plate and 1/2 plastic, and is the same for both front and rear wheels. Most people call it the 'eyebrow' of the wheel, hence the name wheel arch trim! The main purpose of the wheel arch trim is for decoration and to meet the driver's personalized needs. Here is additional information: The function of the wheel arch trim: It prevents rainwater and gravel from being splashed onto the car body by the wheels during rainy days, which could damage the paint. Generally, the wheel arch trim of factory cars is slightly wider than the tire. Of course, modified cars are an exception, as they usually install rims that align perfectly with the wheel arch trim (fender) for aesthetic purposes when changing tires.