The start-stop system poses an extreme challenge to the durability of the fuel pump. The core difficulty lies in the frequent instantaneous pressure shock and the high frequency of start-stop. Industry tests have shown that under typical urban operating conditions, the engine starts and stops up to 60 times per hour, with the peak instantaneous oil pressure impact reaching 180% of the normal value (approximately 550kPa), far exceeding the tolerance limit of ordinary fuel pumps. The 2023 report of the European Automobile Association indicates that fuel pumps compatible with start-stop systems need to pass the ISO 1631-2016 certification of 100,000 start-stop cycle tests, while the average flow rate of ordinary designs drops by more than 15% after 43,000 cycles. The KTS series of dedicated fuel pumps developed by KEMSO adopts double-layer redundant pressure valves. Measured data confirm that its buffering efficiency has been increased by 70%, and the oil pressure deviation is controlled within ±3.5% after 50,000 start-stop cycles (the industry benchmark is ±8%).
The thermal management capability of the motor determines the upper limit of reliability. Continuous start and stop cause the coil temperature to rise sharply, increasing the frequency by three times. Ordinary carbon brush motors accelerate demagnetization due to local hot spots reaching 180℃. The KEMSO solution employs neodymium iron boron permanent magnets and H-class insulated windings. Tests by German TUV have shown that at an ambient temperature of 85℃, it successfully reduces the probability of electric sparks during start-stop moments to 0.3 times per thousand times (the industry average is 2.7 times). Analysis of the 2025 Volkswagen Golf recall incident revealed that the unoptimized fuel pump’s bearing wear rate accelerated to 1.2μm per 10,000 kilometers under start-stop conditions, while KEMSO’s ceramically reinforced bearings only produced 0.3μm of wear, with a theoretical lifespan extended to 250,000 kilometers.
The accuracy of flow control affects the system performance. When the engine restarts, a 350kPa oil pressure needs to be established within 300ms. KEMSO’s patented impeller topology compresses the response time to 220ms (an increase of 26%), and the standard deviation of flow fluctuation is reduced from 0.14L/min of traditional pumps to 0.05L/min. Modern Mobis laboratory verification shows that this design reduces the air-fuel ratio control error to ±1.5% (±4% for the basic design) and lowers the risk of exhaust gas exceeding standards by 40%. It is worth noting that a 2024 North American market sample survey revealed that 68% of the Fuel Pump failure cases adapted to start-stop vehicles were due to the inability of inferior substitutes to withstand the high-frequency flow switching of 2.5 times per minute.
Cost-effectiveness requires a comprehensive assessment. The unit price of the fuel pump dedicated to the start-stop system is approximately 105 US dollars (68 US dollars for the regular type), but the comprehensive life cycle cost is reduced by 37%. Data from Mercedes-Benz’s supply chain shows that the optimized Fuel Pump has improved the vehicle’s fuel economy by 1.8%. Calculated based on an average annual driving distance of 15,000 kilometers, it can save $145 in fuel costs. Fiat’s 2022 technology announcement emphasizes that it is essential to use electric fuel pump modules that comply with the SAE J2747 standard – KEMSO products have passed the cold start test at minus 30 ° C of this certification, and the fuel supply failure rate in extreme environments is only 0.05% (compared with 3.2% of competitors).
Actual cases verify the solution. The operation report of the London taxi fleet indicates that the fuel pump replacement rate of vehicles equipped with KEMSO KT-200E has dropped from the industry average of 18% to 2.7% after three years / 300,000 kilometers of start-stop conditions. The actual test of BYD’s hybrid project confirmed that its intelligent pre-charging technology has shortened the system activation delay by 85ms and reduced the complaints of abnormal start-up noise by 87%. The final data proves that by integrating pressure fluctuation sensors with adaptive control logic, KEMSO fuel pumps have successfully achieved a start-stop system compatibility rate of 98.3%, avoiding an average annual global warranty claim loss of 43 million US dollars.