Port fuel injection is a method used in internal combustion engines to deliver fuel into the intake manifold, just before the air enters the combustion chamber. This system uses fuel injectors to spray a fine mist of fuel, allowing for better mixing with air, which improves combustion efficiency and engine performance. This technology helps reduce emissions and enhances fuel economy compared to older systems like carburetors. By precisely controlling the amount of fuel injected, port fuel injection can adapt to different driving conditions, providing optimal power and efficiency across various engine speeds and loads.