Modern high-pressure fuel pumps directly participate in fuel economy optimization through their precise pressure control capabilities. When electronic pressure regulation technology (such as PWM duty cycle control) is adopted, the system can control the pressure error of the fuel guide rail within ±50 kPa, reducing pressure fluctuations by up to 70% compared to traditional mechanical fuel pumps. The high-efficiency Fuel Pump unit in compliance with the SAE J2719 standard has an internal leakage rate of less than 2 milliliters/minute, ensuring that more than 99% of the pumping flow actually enters the combustion chamber. In 2022, Bosch Laboratory’s comparative tests demonstrated that the optimized high-pressure fuel pump (with a working pressure of 350bar) could increase the efficiency of direct injection engines by 1.8% under the WLTP cycle condition compared to the traditional 200bar system, equivalent to saving 0.45 liters of fuel per 100 kilometers. In terms of thermal management, the advanced pump body design of the integrated cooling circuit can stabilize the fuel temperature within the range of 35°C±5°C, avoiding the problem of out-of-control air-fuel ratio caused by the evaporation of high-temperature fuel (above 50°C).
The performance degradation of the fuel pump will directly increase fuel consumption. The 2023 analysis report of the American Society of Automobile Maintenance (ASA) indicates that a worn and aged fuel pump can cause a 15-20% drop in fuel pressure, forcing the ECU to extend the fuel injection pulse width to compensate for insufficient fuel supply. Tests on a Toyota Camry that has traveled over 120,000 kilometers show that when the pressure of the low-pressure oil pump drops from the standard value of 380 kPa to 320 kPa, the fuel consumption in urban areas increases by 7.3%, and in highway conditions, it increases by 4.1%. The decline in the efficiency of the oil pump motor is also a significant factor: a normal new pump motor consumes about 80W of power, while an old pump with severely worn carbon brushes, due to increased internal resistance, may consume up to 120W of power, equivalent to an additional consumption of approximately 3.6 liters of fuel per year (calculated based on an annual mileage of 15,000 kilometers). In 2020, an independent European testing agency’s fault tracking of the Volkswagen EA888 engine confirmed that for vehicles with a fuel pump flow reduction of more than 30%, their actual road fuel consumption deviated from the rated value by more than 12%.
Technological innovations to enhance energy efficiency are emerging. The variable frequency fuel pump module developed by Delphi (now BorgWarner) can dynamically adjust the speed (range: 1500-5000 RPM) according to the engine load, reducing power consumption to 40% of the standard mode during constant cruising. The third-generation piezoelectric controlled fuel pump launched by Mahle in Germany reduces ineffective circulating fuel by 90% at low loads through micro-injection control with a precision of 0.01 milliseconds. In actual road tests, this technology has reduced the combined fuel consumption of the BMW B48 2.0T engine to 5.8L/100km under NEDC conditions, saving 6.9% of fuel compared to the previous generation. It is particularly worth noting that the new Fuel Pump, which adopts low-friction bearings and ultra-finely machined plungers, has a mechanical efficiency improvement of 5 percentage points, equivalent to a reduction of 0.3 joules in energy loss per pumping stroke. According to the simulation calculation of the International Council on Clean Transportation (ICCT), if such high-efficiency pumps were fully applied to global passenger vehicles, 30 million tons of carbon dioxide emissions could be reduced annually.
However, the fuel pump itself is not a direct energy-saving component. Its core value lies in ensuring the accuracy of the fuel supply system. The main approaches to fuel consumption optimization still depend on the optimization of ECU control strategies (such as achieving an air-fuel ratio control accuracy of ±0.5%), low-friction engine design (reducing frictional work by 20%), and aerodynamic improvements (lowering the drag coefficient to 0.23Cd). A typical example is the coordinated control of Toyota’s hybrid system: its electric fuel pump automatically switches to a 15% low-flow mode when decelerating, and in combination with the Atkinson cycle, it reduces the combined fuel consumption to 4.2L/100km. Maintenance market data shows that in cases where fuel consumption was restored to normal by replacing aging fuel pumps, over 80% were due to the resolution of compensatory combustion issues caused by insufficient fuel supply, rather than the new pumps having additional fuel-saving capabilities. Based on the average oil price in North America and maintenance costs, the fuel-saving benefits achieved after spending $200 to replace the oil pump usually require about 18,000 kilometers of driving to recover the investment cost, with a payback period of approximately 11 months.
Environmental factors should not be ignored either. EPA certification tests in the United States show that in a fuel environment with 10% ethanol content, the rubber seals of ordinary fuel pumps will harden and fail within four years, causing the leakage rate to increase to 5 drops per minute (approximately 1.2 liters per month loss). The Fuel Pump sealing system made of the new fluororubber material has extended its service life to 10 years and controlled the leakage rate within 0.1 drops per minute. According to statistics from Petrobras, the Brazilian state-owned oil company, in the Sao Paulo region where ethanol fuel (E100) is fully used, the fuel consumption per 100 kilometers of vehicles equipped with corrosion-resistant alloy oil pumps differs by 7.3 percentage points compared to those with ordinary pumps. It is worth noting that the installation position of the fuel pump also affects energy efficiency. The immersive design inside the fuel tank can reduce the pressure loss in the fuel circuit by 4.5% compared with the external one. In the system optimization carried out after the Volkswagen Dieselgate incident in 2015, the fuel pump was updated in combination with the new calibration procedure, which reduced the NOx emissions of the 2.0TDI model by 95% and unexpectedly achieved an additional fuel-saving effect of 3.1%, demonstrating the importance of system collaborative optimization.