Government Procurement Case and Bid-Winning Solution Analysis for the CN6 Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicle in Qiqihar — In northern frigid regions, winter operation of sewage treatment vehicles poses the greatest challenge for procurement entities. Located in western Heilongjiang Province, Qiqihar frequently experiences winter minimum temperatures below -30°C. Such extreme cold not only hinders engine starting but also causes hydraulic fluid to congeal and pipelines to freeze, resulting in complete equipment failure. In late 2025, a municipal sanitation department procured a batch of CN6-compliant sewage treatment vehicles and ultimately selected Chengli Special Purpose Vehicle’s customized solution built on the Dongfeng 3308 mm wheelbase chassis. This article uses this case as a starting point to deeply analyze how to select and configure sewage treatment vehicles under severe operating conditions, providing practical procurement references. I. Case Background: Real Requirements Under Extreme Cold Conditions Procuring Entity: A Municipal Sanitation Department (Qiqihar Region) Quantity Required: 3 sewage treatment vehicles Key Requirements: • CN6 emission compliance, meeting local environmental regulations; • Operational capability in extreme low-temperature environments ranging from -35°C to -40°C; • Equipped with freeze-resistant starting systems and low-temperature hydraulic stability features; • Full official vehicle announcement documentation, enabling registration and annual inspection; • Budget capped at approximately RMB 1.033 million total (approx. RMB 300,000 per unit); • Chassis Selected: Dongfeng 3308 mm wheelbase (corresponding to CLW5070GSSD6 series official announcement; upper-body sewage treatment equipment can be adapted based on actual operational needs). Delivery Status: Chengli Special Purpose Vehicle completed production and delivery within 30 days after contract signing. The vehicles are now in active service across Qiqihar’s urban districts and surrounding townships. Customer feedback confirms stable winter performance, with no reported difficulties in cold-starting or hydraulic system failures. This procurement case is not isolated. According to publicly available tender information, municipal sanitation authorities across Northeast China consistently rank “low-temperature adaptability” as the top evaluation criterion when procuring special-purpose vehicles. Chengli Automobile secured this bid by leveraging its manufacturing advantages in Suizhou (zero-inventory dispatch; standard models delivered within 7–15 days) and its specialized cold-region modification solutions. II. Application-Matched Selection Analysis: Light-Duty Municipal vs. Heavy-Duty Industrial vs. Specialized Operations Sewage treatment vehicles have vastly different requirements for chassis, tank, pump assemblies, and low-temperature configurations depending on application scenarios. Below, we compare three typical use cases and provide corresponding parameter analyses and selection recommendations. 1. Light-Duty Municipal Applications (e.g., residential communities, urban streets, small-scale discharge points) Common Chassis: Dongfeng 3308 mm wheelbase (e.g., CLW5070GSSD6 series) Tank Capacity: Approximately 3–5 m³ Recommended Configuration: Imported freeze-resistant hydraulic oil, electrically heated hydraulic lines, low-temperature starting aids (e.g., glow plugs, fuel-fired heaters), and fully automatic sewage separation system. Advantages: Short wheelbase enables high maneuverability in narrow streets; low curb weight ensures fuel efficiency and suitability for frequent repositioning. 2. Heavy-Duty Industrial Applications (e.g., wastewater treatment plants, industrial zones, large-scale sewer networks) Common Chassis: Dongfeng Dorica or Sinotruk HOWO, wheelbase ≥ 3800 mm (e.g., CLW5180GSSD6 series) Tank Capacity: 8–12 m³ Recommended Configuration: High-capacity vacuum pump, reinforced tank (steel plate thickn