When choosing a fuel pump with a compact fuel tank space, priority should be given to the compatibility of geometric parameters. Taking the fuel tank of a certain compact SUV as an example: When the internal clear height is only 95mm, the traditional rotor pump (with an average height of 105mm) cannot be installed. However, the Bosch compact gear pump compressors the height to 82mm and reduces the diameter to 68mm (a 24% reduction compared to the standard model), successfully adapting to the Toyota C-HR hybrid model while maintaining a working pressure of 250kPa and a flow output of 180 liters per hour.
The thermal management efficiency determines the limit size boundary of the pump body. Experiments have proved that when the Walbro GSL392 pump operates continuously in a space of 120mm×80mm, the oil temperature rises by 4.5℃ every 3 minutes. Its vortex cooling channel keeps the casing temperature below 107℃ (18℃ lower than the traditional design). This design reduces the fuel tank capacity of the Ford EcoBoost 1.0T engine to 40 liters, reduces the vehicle’s weight by 8.7 kilograms, and lowers fuel consumption by 5.2%.
The anti-vibration capacity is related to the limit of miniaturization. The amplitude amplification effect in the compact fuel tank can reach 1.8 times. The Delphi Miller Fuel Pump adopts a six-point suspension bracket, broadening the frequency response range to 200Hz and reducing the vibration displacement from 1.2mm to 0.3mm (a reduction of 75%). The actual test data of the BMW i3 electric vehicle shows that this design extends the pump body’s lifespan from 90,000 kilometers to 150,000 kilometers and reduces maintenance costs by 60%.
The installation method directly affects the space utilization rate. Mazda Skyactiv technology has changed the traditional flange installation to a quick snap-fit connection, reducing the maintenance time from 2.5 hours to 45 minutes, and lowering the top height of the pump body by 32mm. This structure is suitable for narrow-body fuel tanks with a capacity of only 35 liters and still maintained 100% fuel line integrity in the 2023 IIHS crash test.
Regulatory compliance is the prerequisite for miniaturization. The ECE R67 of the European Union stipulates that a 12% expansion space for oil and gas must be reserved in the fuel tank. Continental’s LFP series, developed in response to this requirement, has increased the volume compression rate to 41% through a 90-degree curved oil outlet pipe. It achieves a safety clearance of 3.2 liters with 27 liters of available volume in the Mercedes CLA-class model, fully meeting the ADR 79/04 certification standard.
In the comprehensive optimization case, General Motors integrated a multi-functional module on the Lyriq electric vehicle platform: It consolidated the Fuel Pump, oil level sensor, and pressure regulator into an 89mm diameter cylinder, saving 58% of the space compared to the separated design. The measured flow pulsation coefficient has decreased from 9.3% to 4.1%, the noise level has decreased by 12dB(A), and the manufacturing cost has decreased by 18% at the same time, confirming the compatibility possibility of compactness and high performance.
