Government Procurement Case and Bid-Winning Solution Analysis for the CN6 Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicle in Yancheng. On the eve of the Spring Festival 2026, a municipal sanitation department in Yancheng, Jiangsu Province, launched an urgent procurement plan for CN6 Dongfeng 3308 mm wheelbase sewage treatment vehicles to address the high-load operation pressure on urban sewage networks during holidays. The procurement objective was clearly defined: ensuring efficient sewage suction, solid-liquid separation, and preliminary treatment during Spring Festival support operations, while complying with CN6 emission standards and local environmental requirements. After multiple rounds of solution comparison and tendering procedures, the proposal submitted by Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as "Chengli") was ultimately selected, resulting in the delivery of two sewage treatment vehicles built on Dongfeng chassis. This article interprets Chengli’s winning proposal and vehicle configuration based on publicly available tender information from this procurement, providing objective reference for peer procurement decisions. I. Procurement Background and Requirement Analysis Yancheng is located in a coastal region where the urban drainage system faces significant challenges during holidays—especially during the Spring Festival’s mass return-home period. In its tender notice issued at the end of 2025, the municipal sanitation department explicitly stipulated the following core technical requirements for the procured vehicles: Chassis & Emission: Dongfeng chassis with 3308 mm wheelbase, compliant with CN6 emission standards, ensuring unrestricted urban operation. Sewage Treatment Capacity: Capable of sewage suction, filtration, solid-liquid separation, and sewage transfer; minimum single-operation treatment volume of no less than 3 m³. Emergency Support: High operational availability during major holidays such as Spring Festival, coupled with rapid fault response capability. Budget Control: Following local procurement conventions, the budget per unit was capped at approximately RMB 300,000 (tax-inclusive landed price), ensuring cost-effectiveness. Leveraging publicly announced parameters of models such as CLW5070GSSD6 from its product database—and integrating them with the Dongfeng 3308 mm wheelbase chassis—Chengli customized a sewage treatment vehicle solution. This model features complete upper-structure parameters officially listed in the MIIT Announcement, enabling nationwide registration, annual inspection, and commercial operation—another key reason why the client ultimately selected Chengli. II. Core Configuration of Chengli’s Winning Proposal Chengli’s proposal centered on modifying the CN6 Dongfeng 3308 mm wheelbase chassis with specialized upper-structure equipment. Key configurations include: 2.1 Chassis and Powertrain Chassis Model: Dongfeng Dorica series, 3308 mm wheelbase, equipped with CN6-compliant Quanchai or Yuchai engine, rated power approx. 95 kW. Emission Standard: CN6-B phase, fitted with DOC + DPF + SCR after-treatment system, meeting Yancheng’s environmental requirements. Tires and Braking System: 7.00R16 steel-belted radial tires with ABS anti-lock braking system, enhancing operational safety on wet/slippery surfaces. 2.2 Upper-Structure Sewage Treatment System Sewage Tank: Welded Q235 carbon steel construction with internal anti-corrosion treatment; effective capacity approx. 3.5 m³, satisfying single-operation demand. Vacuum Pump and Separation System: Equipped with water-ring vacuum pump, maximum suction depth ≥7 meters, high suction efficiency; solid-liquid separator installed at rear to remove large particulates from sewage, reducing downstream processing load. Cleaning Function: High-pressure cleaning unit mounted on tank top, including 20-meter high-pressure hose, for...