National VI Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicle in Nanchang: Government Procurement Case Study and Selection Analysis. From 2023 to 2024, a municipal sanitation department in Nanchang (hereinafter referred to as “a certain unit in Nanchang City”) procured a total of 12 units of National VI Dongfeng 3308 mm wheelbase sewage treatment vehicles in two batches, for emergency sewer network unclogging, septic tank cleaning, and preliminary river sewage treatment within the urban area. The first batch of six units was delivered in May 2023; the second batch of six units was delivered in January 2024. The total procurement value amounted to approximately RMB 2.4 million (based on publicly available tender information), with an average unit price of around RMB 200,000. This represents one of Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as “Chengli”)’s typical bulk delivery projects in Jiangxi Province. Project Background and Procurement Requirements As a core city in the Central Yangtze River Urban Agglomeration, Nanchang features a complex urban sewer network system. Septic tank blockages frequently occur in older residential communities, and sewage overflow during rainy-season flooding remains a prominent issue. The unit’s existing three outdated vacuum suction trucks—purchased in 2015—had exceeded their service life, suffered high maintenance rates, and complied only with China IV emission standards, thus prohibiting operation on main urban roads. Consequently, in early 2023, the unit initiated a procurement plan with the following key requirements: Emission Standard: China VI compliance, meeting urban driving requirements. Chassis Wheelbase: 3308 mm, balancing maneuverability and payload capacity—ideal for narrow alleys and old urban districts. Tank Capacity: ≥5 m³ (actual capacity approx. 5.5 m³, per official parameters of model CLW5070GSSD6). Functional Integration: Must support sewage suction, transportation, self-unloading, and high-pressure cleaning (i.e., categorized as a “high-pressure cleaning & suction truck”). Budget Control: Unit cost capped at RMB 245,000 (tax-inclusive landed price). Model Comparison and Selection Process During pre-tender market research, the unit evaluated chassis options from Dongfeng, Sinotruk, and Foton. Dongfeng’s 3308 mm wheelbase chassis was ultimately selected due to its large installed base in Jiangxi Province and extensive, densely distributed after-sales service network (nationwide Dongfeng chassis warranty coverage); additionally, the 3308 mm wheelbase offers a small turning radius, ideal for operations in historic urban districts. Chengli’s proposed solution included: Chassis Model: Dongfeng EQ1075SJ3CDF (China VI, 3308 mm wheelbase). Superstructure Configuration: Tank fabricated from WISCO Q235 carbon steel plates, 5 mm thick; equipped with Weilong vacuum pump (suction rate ≥10 m³/h); high-pressure cleaning system (pressure ≥20 MPa). Official Announcement Model: CLW5070GSSD6 (high-pressure cleaning & suction truck). Quoted Price: Approx. RMB 198,000/unit (tax-inclusive landed price, per Chengli’s 2026 pricing system). A local upfitting enterprise quoted approx. RMB 240,000/unit; however, Chengli leveraged its “direct factory sales without intermediaries” advantage to reduce the unit price by approx. RMB 19,000. Ultimately, Chengli won the bid with a total contract value of approx. RMB 2.376 million (for 12 units), saving approx. RMB 27,000 against budget (per publicly available tender information). Delivery and User Feedback Following delivery of the first batch of six units in May 2023, the unit immediately deployed them for septic tank cleaning operations in historic urban districts including Donghu District and Xihu District. According to feedback from the unit’s Equipment Department: Suction Efficiency: Single-operation capacity (full-tank suction +