The fuel cap gasket, also known as a fuel cap seal or O-ring, serves several important functions in a vehicle's fuel system: Pressure Regulation: The gasket helps regulate the pressure within the tank. It allows excess pressure to escape when necessary (such as during temperature fluctuations or fuel evaporation) while maintaining a sealed environment under normal conditions. Prevents Fuel Evaporation: A properly sealed fuel tank cap prevents fuel from evaporating into the atmosphere. Helps maintain fuel efficiency by preventing fuel loss. Protects the Fuel System: By sealing the fuel tank, the gasket helps protect fuel system components from damage or corrosion caused by exposure to moisture, dust, and dirt. Maintain Engine Performance ：The secure seal provided by the fuel tank cap gasket ensures that the engine receives a steady supply of fuel without any air leakage that may affect combustion efficiency and engine performance. Overall, fuel cap gaskets play a vital role in maintaining the integrity and efficiency of your vehicle's fuel system and reducing emissions and environmental impact. Regular inspection and replacement of worn or damaged gaskets is essential to ensure optimal performance