A fuel door is a small door on the exterior of a vehicle that provides access to the fuel tank. It is typically located on the side of the vehicle, near the rear wheel. The fuel door is usually spring-loaded and can be opened by pressing on it. Once the fuel door is open, the fuel cap can be removed and fuel can be added to the tank.
Fuel doors are important because they help to prevent fuel spills and keep the fuel tank clean. They also help to protect the fuel tank from damage. Fuel doors are typically made of plastic or metal and are designed to be durable and weather-resistant.