In the cold start of the low-temperature case, Fuel Pump performance has the most direct influence over response reliability and engine response speed. Experiments confirm that when the ambient temperature is below -20°C, attenuation of flow rates in traditional fuel pumps can be up to 30%, while electrically heated fuel pumps (such as Bosch EVO-9H) can increase the stability of flow rates to ±3% and shorten the start-up time to less than 1.5 seconds. For instance, after Toyota’s recall of 120,000 North American vehicles in 2022 because of a failure of the low-temperature fuel pump, the redesigned pump body included a PTC (positive temperature coefficient) heating device, reducing the fuel viscosity at -30°C from 45 cSt to 8 cSt and the ignition success rate from 78% to 99%.
Materials’ cold resistance is an important indicator. Fuel Pump high-cold use requires the use of sealing rings made from silicone with a -50°C to 200°C resistance rating and nickel-based alloy impellers to avoid low-temperature embrittlement. According to the data of Delphi test, after 500 cold starts of continuous operation in -40°C condition for the pump body of this design, the leakage rate is less than 0.1%, which is 90% higher than that of the ordinary pump body. The low-temperature fuel pump installed in the 2023 Volvo XC90 Arctic Edition has increasingly increased the fuel pressure at -25°C from 35 psi to 55 psi by optimizing the impeller clearance (from 0.15mm to 0.08mm), and decreased the air-fuel ratio fluctuation range to ±0.2.
Fuel preheating technology significantly improves cold start efficiency. The Fuel Pump (such as Denso DFF-5H) with integrated fuel heater is capable of raising the fuel temperature to -5°C from -30°C in 30 seconds, reducing the atomization particle size of the fuel to below 20 microns, and enhancing the combustion efficiency by 15%. In the 2021 polar test, this pump was installed in the BMW i3 Extended Range Edition and reduced fuel consumption by 22% during cold starts and eliminated 40% of CO emissions. Regarding costs, a heat exchanger in the fuel pump will cost between 1.8 times the normal pump cost (approximately 180 US dollars) but buyers can save at most 85 US dollars a year on fuel usage, which equals a 2.2-year payback time for investment.
Having control over pressure and flow dynamically is of maximum priority. The intelligent Fuel Pump (such as VDO FPD-400) adjusts the output pressure dynamically through the temperature sensor. The flow rate increases from 4 L/min to 6 L/min at -20°C to compensate for the reduction of low-temperature fuel’s density (from 0.78 g/cm³ to 0.84 g/cm³). Customer feedback about the Haval H9 in Russia in 2020 had shown that after the intelligent pump was upgraded, the failure rate when starting the vehicle in winter conditions reduced by 72% and the idle speed fluctuation range decreased from ±200 RPM to ±50 RPM. In addition, the two-stage fuel filters (with precision of 50 microns and 10 microns respectively) can be capable of increasing the low-temperature impurities interception rate to 99.5% and extending the fuel injector life to 150,000 kilometers.
Anti-icing design and corrosion resistance enhance reliability. The Fuel Pump for ethanol fuel (E15) has to employ a galvanized steel shell and a ceramic-coated motor in order to prevent electrolytic corrosion caused by the hygroscopicity of ethanol. General Motors’ 2023 research shows that after 1,000 hours of work in ethanol fuel at -18°C, the wear rate of such pump bodies is merely 12% of that of standard pump bodies, and the flow attenuation is controlled within 5%. Concurrently, the structure of the anti-icing valve can prevent fuel vapor from condensing into ice crystals, increasing the start-stop cycle life of the pump body to -30°C by 10,000 times, three times greater than the unprotected design.
Confirmation in the market and updating of standards drive refinement in technology. According to the SAE J2719 standard, low-temperature fuel pump has to endure the 200-hour durability test at temperatures ranging from -40°C to 85°C. In 2022, Bosch launched the HDP-5 series that reduced the failure rate at high temperatures from 0.8% to 0.05% by featuring redundant circuits and is now the luxury model standard fit such as Audi Q7. The industry data shows that the size of the global low-temperature fuel pump market reached 360 million US dollars in 2024, of which the Asia-Pacific cold region demand represented 42%. User testing shows that smart temperature control system fuel pumps can reduce cold start fuel usage by 18% and are therefore the favorite aftermarket upgrade among vehicle owners in climates colder than -20°C.