I. User Scenario and Core Requirements Lhasa sits at an altitude of approximately 3,650 meters, with winter temperatures dropping as low as -15°C to -20°C. Oxygen levels are only about 60% of those at sea level. Under such extreme conditions, conventional vehicles frequently encounter difficulties including cold-start failure, hydraulic system malfunction, and frozen fluid lines. In 2023, a municipal sanitation department in Lhasa issued a public tender for a batch of Fengjing service vehicles, intended for routine inspection, emergency response, and material transportation. Mr. Li, the fleet management supervisor of the department, stated: “We previously used vehicles from other brands; during winter mornings, they often failed to start, hydraulic arms responded sluggishly, and maintenance costs were high. This procurement’s core requirements are: reliable cold-weather starting capability in Lhasa’s winter conditions, stable and dependable hydraulic systems, and a simple, practical maintenance plan.” According to local procurement practices, the budget was capped at approximately RMB 340,000 per unit, requiring integrated chassis-and-body design and full regulatory certification (Announcement) for local registration. II. Vehicle Selection and Solution Overview After multiple rounds of public tendering, Chengli Special Purpose Vehicle Co., Ltd. delivered five Fengjing service vehicles based on Foton chassis (model reference: CLW5040XDYF6 power supply vehicle, compliant with official Announcement parameters). The solution’s key advantages include: 1. Freeze-Resistant Starting Performance To address Lhasa’s low-temperature environment, the vehicles are equipped with cold-weather starting aids, including: - Engine preheating system: Enables smooth engine start within 3–5 minutes even at -20°C. - Fuel line heating: Prevents diesel waxing and ensures uninterrupted fuel flow. - Battery thermal insulation box: Encased in insulating material to minimize battery capacity loss due to low temperatures. Mr. Li reported: “These vehicles have been in operation since last December and successfully endured several extreme weather events with temperatures down to -18°C—all started reliably on the first attempt, with no cold-related failures.” 2. Low-Temperature Hydraulic Stability The hydraulic system is a critical actuation component for service vehicles. Chengli installed an electric heater in the hydraulic oil tank and wrapped all hydraulic lines with thermal insulation sleeves. Low-temperature hydraulic oil (L-HV32 grade) was selected for its excellent fluidity at sub-zero temperatures, ensuring responsive and reliable hydraulic operation. Mr. Li noted: “Previously, hydraulic arms on our older vehicles required repeated extension/retraction cycles before functioning normally in winter. Now, from engine start to full hydraulic actuation takes only about 20 seconds—significantly improving operational efficiency.” 3. Winter Maintenance Plan Chengli developed a customized winter maintenance program for Lhasa customers, including: - Antifreeze freeze-point testing every two months. - Air filter replacement every quarter to mitigate wear caused by high-altitude sand and dust. - Regular brake system bleeding to prevent moisture freezing in air lines. - Nationwide warranty coverage for the Foton chassis; lifetime service support for the bodywork provided by Chengli, with spare parts shipped directly to Lhasa within 24 hours. III. Operational Flexibility and Real-World Usage Data Following delivery, these Fengjing service vehicles primarily perform the following tasks: - Daily inspection: Covering urban and suburban roads, averaging 80–120 km per day. - Emergency response: Winter road de-icing and urgent equipment repairs. - Material transportation: Hauling de-icing agents and anti-skid sand.