Replacing the Fuel Pump can indirectly cause the atomization effect by ensuring optimal stability of fuel pressure and flow rate. For instance, Bosch 044 series. The standard set pressure by the factory is 58 psi and the flow rate 200 L/h. The average particle mean diameter of the atomized in the direct injection engine is 50 microns (SAE J2715 standard). If the machine is upgraded to the high-pressure one (85 psi, flow rate 250 L/h), together with reducing the nozzle aperture to 120 microns from 150 microns, the median diameter of atomized particles can be reduced to 30 microns (reduction of 40%). The combustion efficiency has also increased by 6% (SAE research Report 2023). Ford Ecoboost, using the tested 2.3 T engine fuel pump following air-fuel ratio deviation from compression, was enhanced to 0.3 mm, and 0.8 mm power output fluctuation was decreased by 15% (from 5% to 4.25%).
Dynamic pressure control is the core of atomization optimization. The Denso HP4-i Fuel Pump controls the pressure fluctuation to ± 1 psi (± 5 psi for the normal mechanical pump) by the closed-loop PID algorithm (sampling rate of 1000 Hz). The fuel injection pulse width error was decreased from ± 0.5 ms to ± 0.1 ms, while the atomization uniformity (expressed by the dispersion coefficient) was increased from 0.35 to 0.12 (the smaller value, the more uniform). During the 2024 24 Hours of Le Mans, racing cars that were fitted out with this pump experienced 18% reduced evaporation rate of fuel (from 5% to 4.1%) when making high-speed turns and consumed 0.3 liters less fuel per lap.
The atomization improvement at a low-temperature mode is particularly remarkable. A factory pump, cold-starting at -20℃, increases the diameter of atomized particles to 80 microns via pressure attenuation from 58 psi to 40 psi, while Walbro 450L/h high-pressure pump has a pressure of ≥ 75 psi with a titanium alloy impeller that is temperature resistant from -40℃ to 150℃. Particle size is controlled at 45 microns (close to normal temperature level), and HC emissions during cold start are reduced by 25% (EPA test data). Tesla Cybertruck’s E-Fuel Pump 3.0 forecasts the engine thermal condition by way of AI and accelerates to 95 psi 0.5 seconds ahead of time, enhancing atomization efficiency at -30℃ by 30% (reducing the time for combustion chamber temperature to reach 600℃ by 1.2 seconds).
The new materials upgrade and collaborative systems increase the overall advantages. The Bosch EKP 8.3 electronic pump employs a silicon carbium-coated shaft sleeve (0.02 friction coefficient). Under a pressure of 100 psi, the rate of occurrence of cavitation effect on the impeller is reduced from 5% to 0.2%, which ensures atomization stability. Along with piezoelectric fuel injectors (0.1 ms response time), the fuel evaporation rate is also boosted by 12%, and particulate matter emission (PM) is cut from 4 mg/km to 1.5 mg/km (up to the Euro 7 standard). But the update costs a total of 800 to 1,200 US dollars (with ECU calibration included), and the payback period on just the high-pressure pump replacement is only 40% (a 3% decrease in fuel consumption vs. 8% of system upgrade.
Cost games and compliance checks have to be balanced. The EU Euro 7 regulation under which the atomization uniformity coefficient should be ≤ 0.15 requires the implementation of closed-loop controlled fuel pumps (e.g., Delphi HFP-937, costing 450 euros per unit). Volkswagen Group pulled back 80,000 diesel vehicles in 2023 due to poor atomization. When replaced with a new pump body, NOx emission dropped from 0.12g/km to 0.04g/km, reiterating the worth of emission reduction by high-pressure pumps. If users select non-certified altered pumps (e.g., AEM 320L/h), even though the original expenditure can be reduced by 30%, the rate of fluctuation of atomization efficiency (± 8%) can cause a 25% rise in failure probability of yearly inspection, and the long-term risk is considerable.