Government Procurement Case and Bid-Winning Solution Analysis for the Dongfeng D6 Sewage Treatment Vehicle (Blue License Plate) in Fuzhou. Located on the southeast coast of China, Fuzhou features a subtropical maritime monsoon climate, with high summer temperatures, heavy rainfall, and year-round relative humidity exceeding 70%. This hot-humid environment imposes severe corrosive effects on municipal sanitation vehicles—especially specialized vehicles like sewage treatment trucks that frequently handle sewage and slurry. Their anti-corrosion performance and sealing component durability directly determine equipment service life and operational maintenance costs. This article analyzes the actual procurement cases of two batches of Dongfeng D6 blue license plate sewage treatment vehicles by a municipal sanitation department in Fujian’s Fuzhou City (hereinafter referred to as the 'procuring entity') between 2022 and 2024, elucidating its procurement decision-making logic, vehicle operational performance, and reasons for contract renewal and expanded procurement—providing replicable bid-winning solution insights for government procurements in other coastal regions. I. Initial Procurement in 2022: Addressing Urban Waterlogging and Sewer Network Maintenance In 2022, Fuzhou experienced multiple episodes of intense short-duration rainfall during typhoon season, causing severe water accumulation in low-lying urban areas and frequent blockages in aging neighborhood sewer networks. The procuring entity urgently required a fleet of highly maneuverable, off-road-capable sewage treatment vehicles capable of operating efficiently in narrow alleys and confined spaces. After comprehensive evaluation, three Dongfeng D6 blue license plate sewage treatment vehicles manufactured by Chengli Special Purpose Vehicle Co., Ltd. were ultimately delivered. 1.1 Vehicle Configuration and Official Announcement Parameters Based on Chengli’s MIIT official announcement parameters (model reference: CLW5070GSSD6), the vehicle adopts the Dongfeng D6 chassis, with a wheelbase of 3,308 mm, powered by a Quanchai 130-horsepower diesel engine meeting China VI emission standards. The tank capacity is approximately 4.5 m³, equipped with a high-power sewage pump offering a maximum suction depth of 7 meters and self-priming height of 6 meters. Overall vehicle dimensions measure approximately 5,995 × 2,000 × 2,400 mm; it qualifies for a blue license plate and may be operated with a Class C driver’s license, with no urban access restrictions. 1.2 Procurement Background and Budget To meet emergency operations during the rainy season, the procuring entity set a budget cap of approximately RMB 395,000 (per publicly disclosed tender information). Chengli offered a unit price of around RMB 115,000 per vehicle (tax-inclusive landed cost), totaling approximately RMB 389,000 for three units—fully compliant with the budget requirement. II. Operational Feedback: Durability Validation under Hot-Humid Conditions From July 2022 to June 2024, these three Dongfeng D6 sewage treatment vehicles accumulated over 18 months of operation in Fuzhou, enduring three complete typhoon seasons. Their operational frequency significantly exceeded that of comparable models deployed inland. Key performance feedback from the procuring entity includes: 2.1 Anti-Corrosion Coating Performance Fuzhou’s high-salinity fog and high-humidity environment severely corrodes metal components. In response to coastal users’ requirements, Chengli applied enhanced anti-corrosion coatings to critical areas—including the tank body, pipe connection fittings, and key chassis components—and validated their performance via salt spray testing. In actual use, only minor surface rust appeared on vehicle exteriors—significantly outperforming other brands’ standard corrosion-protection treatments. Maintenance records confirm zero structural component replacements due to corrosion over the two-year period. 2.2 Sealing Compo