Government procurement case of Foton Fengjing service vehicles in Wenzhou: Interpretation of high-load operation solutions under hot-humid conditions. In coastal Wenzhou, municipal sanitation departments face unique challenges—high humidity, salt fog corrosion, and frequent rainy seasons—which significantly reduce the service life and operational efficiency of conventional service vehicles. In 2025, a municipal sanitation department launched a procurement program for service vehicles, focusing on resolving rusting, seal failure, and reliability issues of aging equipment under hot-humid conditions and during high-load operations in the rainy season. Based on publicly available tender information, this article interprets the complete procurement process and Chengli Special Purpose Vehicle’s tailored solution. I. Pain Points of Aging Equipment: 'Incompatibility' Under Hot-Humid Conditions Wenzhou is located along the southeast coast, with an annual average relative humidity exceeding 80% and high airborne salt content due to its maritime climate. Previously deployed service vehicles (non-Foton branded) used by this department exhibited the following common issues: • Rust protection coating failure: Significant rusting appeared on frames, chassis, and body panels within 2–3 years, compromising structural integrity and increasing maintenance costs. According to local procurement standards, such vehicles are typically designed for an 8–10-year service life; however, in practice, rust-related repair frequency is approximately 30% higher than in inland regions. • Poor durability of sealing components: Rubber seals on doors, windows, and electrical interfaces aged and cracked rapidly under alternating hot-humid conditions, causing cabin water infiltration during rainy seasons and moisture-induced failures of electronic equipment. Customer feedback indicated short-circuit risks in instrument clusters and control systems after prolonged rainfall. • Suboptimal performance during high-load rainy-season operations: During Wenzhou’s flood season (May–September), heavy rainfall is concentrated, requiring frequent deployment of service vehicles for drainage emergency response, road inspection, and material transport. Aging vehicles experienced reduced engine cooling system efficiency under hot-humid conditions, resulting in noticeable power loss; in severe cases, mid-operation shutdowns for cooling were required, disrupting workflow continuity. These pain points not only lowered operational efficiency but also increased total lifecycle costs. Consequently, the new procurement requirements explicitly mandated vehicles specially adapted to hot-humid environments—particularly regarding anti-corrosion, sealing, and thermal management systems. II. New Requirements Research Process: From 'Generic' to 'Specialized' Prior to procurement, the municipal sanitation department collaborated with technical experts and frontline operation teams to conduct a two-month requirements research initiative. Key focus areas included: • Anti-corrosion standards: Chassis must feature electrophoretic coating plus underbody armor coating; body panels must be galvanized on both sides; critical bolts must be stainless steel; and all components must pass neutral salt spray testing (≥480 hours without red rust). Per MIIT announcement specifications, the Foton Fengjing service vehicle (e.g., model CLW5040XXH) chassis complies with these standards. • Sealing component requirements: Door seals must use ethylene propylene diene monomer (EPDM) rubber, offering superior weather resistance compared to conventional chloroprene rubber; electrical connectors must achieve IP67 ingress protection rating to ensure waterproofing even during heavy rain. • Thermal management and load capacity: The engine cooling system must incorporate a large-capacity radiator and electric cooling fans, ensuring continuous operation for six hours under full-load conditions at ambient temperat