I. Case Background: Three-Year Field Usage Record of a Municipal Sanitation Department in Yinchuan City. Yinchuan is located in the northwest high-cold region, where winter minimum temperatures can reach -25°C to -30°C—imposing stringent requirements on the service vehicle’s frost-resistant starting capability and hydraulic system stability. In early 2023, a municipal sanitation department in Yinchuan procured five Foton Fengjing service vehicles (Model: CLW5040XDYJ6, modified based on the Foton Fengjing G9 chassis) through public tender for road inspection, equipment maintenance, and emergency material transportation within its jurisdiction. All vehicles were delivered and entered service in February 2023 and have now been continuously operated for over three years, accumulating approximately 150,000 km in total mileage. Based on the unit’s provided maintenance and repair records, we have compiled comprehensive fault data to provide objective vehicle selection references for other government procurement entities. The unit’s procurement manager stated: “We selected Chengli Special Purpose Vehicle Co., Ltd. primarily due to its commitment to nationwide original-equipment manufacturer (OEM) chassis warranty and lifetime upper-body structure service. In actual use, apart from some initial starting issues during winter, overall performance has met expectations.” II. Three-Year Real-World Maintenance Records and Fault Type Distribution The following data are extracted from the unit’s paper-based maintenance logs covering February 2023 to January 2026, documenting a total of 24 repair events across various fault categories. These are summarized into five major types: Fault Type | Occurrence Count | Percentage of Total Faults | Typical Problem Description | Resolution Duration (Days) ---|---|---|---|--- Winter Starting Difficulty | 6 | 25% | Failure to start below -20°C due to battery discharge and diesel fuel filter waxing | 1–2 Hydraulic System Leakage | 5 | 20.8% | Seal ring aging in lifting cylinders; oil leakage caused by viscosity changes in hydraulic oil at low temperatures | 2–3 Chassis Component Wear | 4 | 16.7% | Premature wear of brake pads and clutch plates (associated with frequent stop-start cycles) | 1 Electrical System Faults | 4 | 16.7% | Intermittent failure of lighting relays and wiper motors | 1–2 Others (e.g., abnormal noise, HVAC issues) | 5 | 20.8% | Door seal strip detachment, insufficient heater airflow | 1–3 Total | 24 | 100% | — | Average 1.8 days Key Finding: Winter-related faults (starting difficulty + hydraulic leakage) account for 45.8% of all faults—directly attributable to Yinchuan’s low-temperature environment. Notably, however, all faults were resolved within 1–3 days, with no prolonged downtime caused by parts shortages. III. Chengli After-Sales Response Speed: Real-World Data from Repair Initiation to Completion According to maintenance records, the unit’s after-sales process with Chengli is as follows: • Phone Response: Upon calling the hotline, technical guidance is typically provided within an average of 20 minutes (extended to 40 minutes during peak winter periods). • On-Site Service: Chengli operates an authorized service station in Yinchuan, located approximately 15 km from the unit. For routine faults (e.g., electrical components), technicians are dispatched on the same day; for complex issues (e.g., hydraulic leakage), on-site visits are scheduled for the next business day. • Repair Turnaround Time: From fault reporting to full resolution, the average duration is 1.8 days. For winter starting difficulties, the service station resolved the issue by installing low-temperature preheating devices and replacing diesel filters rated for -35°C.