Mechanical Fuel Pump VS Electrical Fuel Pump


Post created: 25 January 2021

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Learn more about mechanical and electrical fuel pumps in this article, what the difference is and know what your vehicle uses so you can make more informed decisions.
First of all, fuel pumps are used to move fuel from the tank and feed it into the combustion part of the engine. Knowing whether your car uses a mechanical or electrical fuel pump will help prevent complete stalling of your car and overall poor performance due to the installation of the wrong pump.

What are the differences?

Mechanical fuel pumps are usually found on older vehicles, while newer vehicles generally use electrical fuel pumps due to them having more power and thus needing a high-pressure fuel input. For electrical fuel pumps, a computer system is used to regulate the flow rate and how high the pressure is, ensuring the is provided with exactly the right amount of fuel.

There are various differences between mechanical and electrical fuel pumps. Mechanical fuel pumps are generally mounted on the side of the engine, and work by drawing fuel out from the bottom of the tank using a suction process. A diaphragm creates the suction, and a valve stops the fuel from flowing back into the tank once the pump has filled up. The collected fuel is then discharged to the carburettor or through a second valve. This process is repeated as the vehicle moves, and an arm is used to drive the pump, increasing as the revs per minute are elevated. This means that there is enough fuel going into the engine even at higher speeds when there is a demand for more.

Electrical in-tank fuel pumps work in a different way. They are generally located at the top of the fuel tank, occasionally via the trunk floor or a hole under one of the seats. The pump will usually be mounted on a bracket in a case, which sits inside the fuel tank. These pumps don’t rely on the mechanical systems for drawing fuel, and are instead designed to be permanently immersed in fuel. As soon as electricity is directed to the pump, the motor starts up and begins to propel the fuel up the lines to the engine. The electronics can determine the rate at which fuel is needed, and increase or decrease pump speed accordingly.

The biggest difference between electrical and mechanical fuel pumps is that mechanical pumps rely on moving parts to pull fuel out of the tank and into the engine, whilst electrical pumps use electricity and computer power to push fuel to the engine.

Now that you know the difference, you can figure out which fuel pump your car needs and visit AutoZone for the right pump for your car.

Not sure what kind of pump your car uses? No problem! Visit or contact your nearest AutoZone with the make, year and model of your vehicle and we’ll gladly help you with expert advice.