Extreme low-temperature environments induce multiple mechanical failures. At -30℃, the Fuel viscosity surges by 300% (gasoline rises from 0.6mPa·s to 2.4mPa·s), forcing the starting torque requirement of the Fuel Pump motor to increase by 250%. Measured data shows that the peak locked rotor current of traditional brushed motors at -25℃ reaches 45A (only 18A at normal temperature), and the wear rate of carbon brushes increases by 400%. Statistics from the North American Transportation Association show that the failure rate of diesel engine fuel pumps surges to 21% in extremely cold weather (below -25℃), which is 3.3 times higher than that in normal temperature environments. Among them, 87% are due to open circuits in the armature winding (cold shrinkage stress causing enameled wire breakage) or commutator rupture (a 60% decrease in material brittle strength). During the cold wave in Canada in 2021, AAA rescue records showed that the number of daily fuel system failure requests reached 12,500, among which 68% were confirmed to be fuel pump failures.
High-temperature environments accelerate the deterioration of materials and chemicals. Under the working condition of 90℃, the fuel density decreased by 4.2% (from 740kg/m³ to 709kg/m³), resulting in a 28% attenuation of the volumetric efficiency of the oil pump. At 140℃, the magnetic flux of the permanent magnet decreases by 15%, forcing the motor speed to drop by 25% to maintain power balance. The measured flow rate attenuation reaches 22%. Tests by the Society of Automotive Engineers (SAE) show that when the continuous operating temperature is > 100℃, the rate at which alcohol fuel generates gum increases fivetimes (with an average daily deposition amount > 120mg), causing the pressure difference between the pump’s inlet and outlet to rise from 3.0bar to 4.8bar. Among the cases of Mercedes-Benz M276 engine stalling when hot, 93% were caused by clogged oil pump filters, and the incidence rate in desert environments was 190% higher than that in temperate regions.
The temperature sensitivity of electronic systems varies significantly. When the electronic control unit (ECU) is at -40℃, the conduction delay of the MOSFET increases to 150ns (the reference at 25℃ is 40ns), resulting in a 58% lag in the PWM control response of the oil pump, and the standard deviation of the pressure fluctuation expands to ±1.2bar (±0.3bar at room temperature). Conversely, in a high-temperature environment, the thermal drift error of the pressure sensor reaches ±7% (with a full-range deviation of 0.7bar at 90℃), and the frequency of triggering the air-fuel ratio correction increases by 300%. Tesla Battery Day 2022 disclosed data: The thermal management system of Model 3 kept the operating temperature of the Fuel Pump (range-extended version) stable at 45±5℃, reducing the failure rate by 79% compared with traditional fuel vehicles.
Regional big data reveals significant distribution differences. The European Traffic Accident Data Centre (ERCDC) analyzed 2 million malfunctions: In the Scandinavian region (with an average annual temperature of 2℃), the failure rate of oil pumps in winter was 38%, while in the Mediterranean region (with an average annual temperature of 24℃), the failure rate in summer reached 53%. In Heilongjiang region of China, the abnormal rate of oil pump current under the cold start condition of -30℃ is as high as 32%, while in Hainan Island during the hot season, the fuel evaporation loss rate exceeds the national standard limit by 220%. User feedback from Chevrolet Silverado in Dubai shows that the failure rate of air conditioning condensate water seeping into the oil pump circuit is 140% higher than that in cold regions.
The upgrading of materials technology is changing the failure mode. The new brushless fuel pumps (such as Delphi GDS210) adopt neodymium iron boron permanent magnets, and the magnetic flux loss is only 5% at -40℃ (the loss of traditional ferrite is 35%). The thermal deformation of the polyetheretherketone (PEEK) impeller at 150℃ is less than 0.05%, avoiding high-temperature friction jamming. The fuel pump of the Ford F-150 Hybrid version has been equipped with a semiconductor cooling device, which has broadened the ambient temperature range to -40℃ to +85℃ and increased the mileage between failures from 80,000 kilometers to 150,000 kilometers. The 2023 report of Bosch Laboratory confirmed that for the high-end Fuel Pump with an integrated thermal management module, the standard deviation of the failure rate across the entire temperature range has decreased to ±0.8% (±18% for the previous generation product).