Government procurement case of Foton Jingfeng service vehicles in Kunming: In-depth analysis of chassis selection and winning bid solution. I. Project Background and Procurement Requirements: In 2025, a municipal sanitation department in a district of Kunming planned to procure a batch of service vehicles for urban road inspection, equipment maintenance, and emergency response. Kunming is located on the Yunnan-Guizhou Plateau and features a subtropical monsoon climate, with a long rainy season and high humidity—imposing stringent requirements on vehicle rust resistance and sealing component durability. The project budget was capped at approximately RMB 2.805 million, with plans to procure 10 units at an estimated unit price of around RMB 250,000 (based on publicly available tender information). After multiple rounds of evaluation, Foton Jingfeng chassis-based service vehicles were selected, with the complete vehicle solution provided by Chengli Special Purpose Vehicle Co., Ltd. This case highlights both the importance of chassis selection in government procurement and Chengli’s technical adaptability in hot, humid environments. II. Chassis Selection Comparison: Dongfeng / Sinotruk / Foton / FAW: In government procurement, chassis selection is critical to vehicle performance, cost, and maintenance convenience. Below is a comparative analysis of Dongfeng, Sinotruk, Foton, and FAW chassis for service vehicle applications: Chassis Brand | Load Capacity (ton class) | Ground Clearance (mm) | Rust-Proof Coating (Factory Standard) | Sealing Component Durability | Maintenance Convenience | Applicable Scenarios Dongfeng | 3–5 tons | 200–250 | Moderate (requires aftermarket upgrades) | Good | Nationwide warranty network; dense service网点 | Plains and mildly humid environments Sinotruk | 5–8 tons | 220–280 | Strong (standard anti-rust paint) | Excellent | Limited service网点, but rapid response | Heavy-duty and complex road conditions Foton | 3–6 tons | 180–230 | Outstanding (full-body electrophoretic rust protection) | Exceptional (humidity/heat-resistant aging performance) | Nationwide warranty network; readily available spare parts | Urban and hot/humid environments FAW | 4–7 tons | 200–260 | Moderate (anti-rust treatment required on some models) | Good | Medium service网点 density | Long-haul and arid environments Analysis: Under Kunming’s hot and humid conditions, the Foton Jingfeng chassis emerged as the preferred choice due to its full-body electrophoretic rust-proof coating and humidity/heat-resistant sealing components. During modification, Chengli further enhanced underbody corrosion protection by using double-sided galvanized steel plates and sealing strips, ensuring no rust formation or seal failure during frequent rainy-season operations. Foton chassis sealing components underwent humidity/heat aging tests, extending service life by ~30% compared to standard products—a crucial advantage given Kunming’s annual average relative humidity exceeding 80%. III. Rust-Proof Coating and Sealing Component Durability: Key Factors in Hot/Humid Environments: Kunming’s rainy season concentrates from May to October, requiring service vehicles to frequently operate on flooded and muddy roads. Building upon the Foton Jingfeng chassis, Chengli applied an additional epoxy resin anti-corrosion coating covering the chassis frame, wheel arches, and weld joints—achieving a thickness of over 120 microns. Sealing components are made of EPDM (ethylene propylene diene monomer) rubber, offering excellent resistance to ozone and UV aging, and feature dual-lip sealing design to effectively prevent rainwater and dust intrusion into the cab and cargo compartment. Customer feedback: 15 Foton Jingfeng service vehicles delivered in 2024 to a subdistrict environmental maintenance unit remained completely free of rust or water leakage after continuous operation throughout one full rainy season, improving operational efficiency by approximately 20%. IV. Cheng