A faulty fuel pump can indeed cause a sudden drop in fuel economy. When a fuel pump starts to fail, it may not deliver fuel at the correct pressure or flow rate, which can directly impact engine performance and efficiency. Conventionally, a fuel pump will generate flow to the engine within the range of 30-60 psi for most gasoline engines, enabling easy operation of the engine in smooth tune and efficiency. When pressure and rate of flow are compromised for that same pump, it simply becomes harder for the proper quantity of fuel to reach the correct areas of the engine; the result is poor combustion with reduced fuel efficiency. Studies have shown that a drop in fuel pump performance can lead to 15-20% less fuel efficiency in some cases.
In fact, a 2018 Ford survey indicated that over 30% of consumers who experienced a sudden drop in fuel economy reported issues with the fuel pump. This decrease in fuel economy can occur with a clogged, worn-out fuel pump, or its internal components such as a motor or diaphragm that may be damaged. A malfunctioning fuel pump may result in the engine misfiring, running rich, or not getting fuel, all of which will affect fuel economy.
For instance, a Chevrolet Silverado with a malfunctioning fuel pump may exhibit hesitation, sputtering, or complete stalling of the engine, all of which make the motor unable to maintain its usual fuel economy. If the proper amount of fuel is not being adequately delivered to the combustion chambers, the engine tries to use more fuel to balance it out for the loss in power, which leads to higher fuel consumption. The economy loss could reach 30 percent or more in some cases.
The fuel filter is also supposed to maintain the efficiency of the fuel pump. A clogged fuel filter restricts fuel flow to the engine, which in turn makes the pump work harder. According to a 2009 report on Honda Civics, a clogged fuel filter may reduce the flow rate of the pump by up to 40%, which would eventually cause an engine performance malfunction and notably reduce fuel efficiency. Additional stress on the fuel pump will only lower its performance, causing higher consumption and increasing operation costs.
A sudden decline in fuel economy can also point to a malfunction of the fuel pump due to possible debris or contaminants within the fuel system. A study done by AAA in 2017 found that vehicles running on poor-quality fuel or always driving through areas with a high level of dirt and grime increase the possibility of fuel pump failure due to contaminants by 40%. These contaminants clog the pump and make it unable to deliver appropriate amounts of fuel, which in turn reduces engine efficiency.
Fuel pump failure is usually characterized by a gradual decline in fuel economy, but it can also lead to more sudden problems such as engine stalling or loss of power. A poorly working fuel pump needs to work harder to pump fuel to the engine, which puts extra load on the overall fuel consumption of the vehicle. This could result in a considerable increase in fuel costs, especially if the problem persists without being resolved.
The cost of repairing or replacing a faulty fuel pump will vary, but on average, it ranges from $300 to $800 depending on the model and labor costs. A new fuel pump usually lasts for 100,000 miles before any wear starts to show, but problems can arise much earlier, especially if regular maintenance is neglected. Replacing a fuel pump promptly can prevent further damage to the engine and help restore fuel economy.
If you think that your fuel pump is affecting your fuel economy, you should consult a mechanic to diagnose the issue. Preventive maintenance, including replacement of the fuel filter and using high-quality fuel, can avoid these issues and ensure the longevity of the fuel pump. For more information on high-quality replacement parts, you can visit Fuel Pump.