Fuel Pump effectiveness directly influences a vehicle's MPG because it ensures that the correct quantity of fuel is fed to the engine for proper combustion. Efficiency in the fuel pump ensures appropriate fuel pressure in the engine, usually within the range of 30-80 psi with regard to the make of the vehicle. This consistency allows the engine to have the right mix of fuel and air, thus highly optimizing the combustion of fuel in a manner that there is least wastage. On the other hand, a weak or failing Fuel Pump breaks this balance, resulting in decreased fuel efficiency that can extend even up to a drop of 10% to 20% in MPG.
As an example, if the Fuel Pump struggles to deliver fuel at proper pressure, an engine can run lean-in other words, there is too much air and not enough fuel in the combustion chamber. This will make an engine do more work to consume more fuel to get the same amount of power, hence affecting MPG directly. Reciprocally, if the Fuel Pump delivers too much fuel, then the engine runs rich, leading to incomplete combustion. This causes a waste of fuel and further reduces efficiency.
A real-life example was the 2020 Subaru and Toyota recalls due to some faulty Fuel Pumps that eventually gave inconsistent fuel delivery. Drivers reported not getting the normal economy of fuel, aside from stalling and poor performance by the engines. This basically pinpoints the importance of maintaining the efficiency of a Fuel Pump.
Regular maintenance of the fuel filters, every 30,000 to 50,000 miles, keeps the Fuel Pump running smoothly by preventing clogs that force the pump to work harder. A plugged filter can decrease fuel flow up to 30%, further impacting MPG and overall engine performance. Making sure the Fuel Pump relay and all electrical connections are operating correctly also serves to maintain steady fuel delivery without any unnecessary fuel waste.
What Henry Ford said in relation to fuel economy, therefore, applies: "If everyone is moving forward together, then success takes care of itself." This means that when each part, the Fuel Pump included, is doing well, then the whole system reaps the benefit to an end of better MPG and overall vehicle performance.
Learn more about Fuel Pump efficiency and how to optimize MPG at Fuel Pump.