The fuel pump installed on a Mercedes car is the heart of the vehicle's power supply line. Mounted halfway between the fuel tank and the engine, the Mercedes fuel pump circularizes the required burn materials used by the engine to generate power. Because engine performance depends in large part on the fuel component of the burn materials, the Mercedes fuel pump is considered the chief fuel injection part likely to determine the amount of horsepower that the Mercedes can produce.

Mercedes fuel pumps differ in types according to the engine class of the vehicle. Since the volatility of gasoline is not the same as that of diesel, Mercedes fuel pumps are categorized into diesel and gasoline fuel pumps. In a Mercedes gasoline engine the fuel is highly volatile, having rich vapor pressure at ambient temperature. Because of the high fuel boost, the fuel line of the Mercedes gasoline engine is designed completely sealed from the tank to the carburetor, or to the fuel injection system, depending on the type of fuel delivery system installed on the car. With the fuel line shut tight, the gasoline fuel is prevented from escaping the pipeline.

The Mercedes fuel pump adapts to the high-pressure condition of the gasoline engine through a spring-and-diaphragm mechanical pump, which purges the line of vapor in the event of a vapor lock'a condition in which the fuel vaporizes owing to abnormally high ambient temperature. In this setup, the Mercedes fuel pump is actuated by a pushrod. Motor-driven and solenoid-operated diaphragm and plunger Mercedes fuel pumps are also available that can be mounted near the main fuel tank to minimize vapor lock in the fuel lines. The fuel line of some Mercedes cars that run on gasoline are likewise ready to be fitted with an electric Mercedes fuel pump submerged in the fuel tank itself. In fuel injection systems, a submersible in-tank Mercedes fuel pump is used to boost the high-pressure main fuel injection pump. The in-tank Mercedes fuel pump is available in gear, plunger, sliding vane, and impeller types.

Diesel engines generally uses the same fuel pump configuration. But because the air component of the diesel fuel needs to be compressed before it is pumped into the engine, the diesel Mercedes fuel pump is fitted with a needle valve that is designed to allow the inlet of high-boost air into the fuel line. When the diesel is injected at high pressure through an injection nozzle into the highly compressed air in the combustion chamber, the needle valve of the Mercedes fuel pump serves as failsafe to fuel explosion. In the event that the required high pressure is already reached in the injection nozzle, the needle valve opens and fuel is sprayed into the combustion chamber.

Primary beef on stock Mercedes fuel pumps, both for diesel and gasoline engines, are the noise and engine pulsation during fuel line operations. In the aftermarket there is also a Mercedes fuel pump type that, instead of a gear, plunger, or vane, operates on a turbine. The turbine Mercedes fuel pump may be considered performance grade, based in large part on the upped quality of fuel delivery that it presents. But its capacity to supply the engine with optimal fuel is typically the same as most Mercedes fuel pumps.