Government Procurement Case and Winning Bid Solution Analysis for CN6 Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicle in Tianjin. In recent years, with the enhancement of urban environmental governance requirements, demand for sewage treatment vehicles in municipal sanitation sectors has grown significantly. As a major northern city, Tianjin’s low-temperature winter conditions impose higher demands on specialized vehicles’ frost-resistant starting performance and low-temperature hydraulic system stability. Based on a real government procurement case, this article analyzes the operational condition-matching logic adopted by a municipal sanitation department in Tianjin when procuring CN6 Dongfeng 3308 mm wheelbase sewage treatment vehicles, and interprets Chengli Special Purpose Vehicle Co., Ltd.’s winning bid solution. I. Procurement Background in Tianjin: Operational Condition Matching Is Critical In 2025, a district-level municipal sanitation department in Tianjin planned to procure a batch of sewage treatment vehicles for pipeline desilting in old residential communities and emergency sewage treatment in industrial parks. The procuring entity explicitly required compliance with China VI emission standards and emphasized three key technical requirements: frost-resistant starting capability, low-temperature hydraulic system stability, and a winter maintenance plan. This is because Tianjin’s winter temperatures frequently drop below −10°C; hydraulic system failure under such low temperatures would directly impair operational efficiency. Following an open tender process, Chengli Special Purpose Vehicle Co., Ltd. successfully delivered three sewage treatment vehicles built on the Dongfeng 3308 mm wheelbase chassis, based on its targeted technical proposal. According to publicly available tender information, the total budget was controlled within approximately RMB 396,000, with an average unit price of around RMB 110,000. II. Operational Condition-Matching Solution: Light-Duty Municipal / Heavy-Duty Industrial / Special Operations Based on actual operational scenarios in Tianjin, Chengli engineers categorized working conditions into three types and matched vehicle specifications accordingly: 1. Light-Duty Municipal Operation: Pipeline Desilting in Old Residential Communities For narrow roads and shallow sewage pipelines typical of Tianjin’s old residential neighborhoods, Chengli recommended the Dongfeng 3308 mm wheelbase chassis (model CLW5070GSSD6), keeping overall vehicle length under 6 meters and ensuring a small turning radius. Key configurations include: • Frost-Resistant Starting System: Standard-equipped with a low-temperature cold-start device featuring imported glow plugs, enabling reliable one-time engine start at −25°C. • Low-Temperature Hydraulic Stability: Hydraulic tubing insulated with thermal wrap and filled with low-temperature hydraulic oil (pour point −35°C) to prevent oil solidification and system jamming. • Winter Maintenance Plan: Chengli provides complimentary upgrade services, including replacement with winter-grade antifreeze and inspection of battery insulation enclosures. Customer Feedback: During the January 2025 cold snap in Tianjin (−15°C), the vehicle operated continuously for 8 hours without fault; hydraulic system response speed remained identical to that under normal ambient temperatures. 2. Heavy-Duty Industrial Operation: Emergency Sewage Treatment in Industrial Parks A certain industrial park in Tianjin required high-capacity, high-suction-capability sewage treatment vehicles due to enterprises discharging highly concentrated wastewater. Chengli matched an extended-version Dongfeng 3308 mm wheelbase chassis equipped with a high-power vacuum pump (suction depth ≥ 8 meters). Key configurations include: • Heavy-Duty Hydraulic System: Dual-gear hydraulic pump configuration delivering a working pressure of up to 20 MPa—suitable for long-distance conveyance of high-viscosity sewage. • Frost-R