The damage of high temperature to the internal components of Fuel pumps has been confirmed by a number of studies. According to the experimental data of SAE International, when the working temperature of the fuel pump exceeds 120°C, the deformation probability of the internal plastic gears increases by 40%, resulting in the flow accuracy error expanding from ±3% to ±8%. Meanwhile, the viscosity of the motor bearing grease decreases by 50% and the wear rate increases by three times. For instance, a German brand recalled 120,000 vehicles in 2020 due to a heat-resistant design defect in the fuel pump. The fault cases showed that under continuous high temperatures (ambient temperature > 45°C), the lifespan of the fuel pump was shortened from 100,000 kilometers to 60,000 kilometers, and the failure rate soared by 25%.
The electronic components of the fuel pump are particularly sensitive to high temperatures. A fault analysis by Tesla in 2022 pointed out that in an environment above 85°C, the ESR (Equivalent series resistance) of the capacitor in the fuel pump control module (PCB board) of Model 3 increased by 30%, causing the current fluctuation range to increase from ±2A to ±5A, which in turn led to overheating and carbonization of the coil, and the maintenance cost was as high as 800 US dollars. Similarly, simulation tests of Bosch fuel pumps show that for every 10°C increase in temperature, the risk of demagnetization of permanent magnets increases by 15%, and the motor efficiency decreases by 4% to 6%. The industry standard ISO 16330 stipulates that the fuel pump should be able to stably output pressure (such as 350 bar) within the range of -40°C to 110° C. However, beyond this limit, the fit clearance between the plunger and the cylinder block expands by 0.02 mm due to thermal expansion, the leakage increases by 18%, and the fuel economy is lost by approximately 5%.
Upgrading the heat resistance of materials is the mainstream solution to deal with high temperatures. For instance, in the hydrogen fuel model Mirai launched by Toyota in 2023, a Fuel Pump motor coated with silicon carbide (SiC) is adopted, which increases the temperature tolerance from 130°C to 180°C, enhances the power density by 20%, and reduces noise by 10 dB. Schaeffler Group’s research shows that using perfluoroether rubber (FFKM) instead of nitrile rubber sealing rings can maintain sealing performance for over 5,000 hours at 150°C, with a leakage rate of less than 0.1 mL/min and a cost increase of approximately 15%. In addition, the active cooling system jointly developed by BMW and Mahle, by integrating micro heat sinks (with a 30% increase in surface area), reduces the peak temperature of the fuel pump from 135°C to 98°C and extends the failure interval to 150,000 kilometers.
Market data further verify the necessity of high-temperature protection. The Frost & Sullivan report indicates that in 2023, global cases of fuel pump failures caused by high temperatures accounted for 17% of the total automotive electronic failures, and the maintenance costs increased by an average of 9.3% annually. For instance, during the extreme high temperatures in Arizona, USA in the summer of 2022 (with an average daily temperature of 47°C), the demand for fuel pump replacement soared by 34% year-on-year. Insurance claims data shows that the median cost of a single replacement was $1,200, and the high temperatures accelerated fuel evaporation, raising the probability of cavitation inside the pump from 5% to 12%. Industry forecasts suggest that by 2027, the market size of high-temperature resistant fuel pumps will exceed 2.9 billion US dollars. Among them, products adopting liquid cooling cycle technology (such as Delphi’s EMD series) will account for 23% of the share. Their designed operating temperature limit reaches 160°C, and the flow stability error is controlled within ±1.5%.