Case Study and Bid-Winning Solution Analysis for Harbin’s National VI Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicle Government Procurement In winter 2025, a municipal sanitation department in Harbin publicly procured a batch of National VI emission-compliant sewage treatment vehicles for urban drainage network and septic tank cleaning, suction, and solid-liquid separation operations. The project budget was capped at approximately RMB 1.718 million, with plans to procure five units based on the Dongfeng 3308 mm wheelbase chassis. After multiple rounds of technical evaluation and commercial negotiations, Chengli Special Automobile Co., Ltd. successfully delivered the vehicles. This article analyzes the bidding background, solution comparisons, and technical details to provide reference for procurement entities across Northeast China. I. Project Background and Procurement Requirements The municipal unit’s existing older vacuum trucks suffered from difficulties starting in winter, hydraulic system leakage, and low solid-liquid separation efficiency. The current procurement explicitly required: • Chassis: Dongfeng 3308 mm wheelbase, National VI emission standard, compliant with Harbin urban traffic requirements; • Tank: Effective capacity ≥3 m³, with sealed, freeze-resistant design; • Core Functions: Integrated vacuum suction, solid-liquid separation, and high-pressure cleaning; • Winter Adaptability: Normal engine start-up at -30°C ambient temperature; stable hydraulic system performance at low temperatures; freeze-proof piping; • After-sales Service: Nationwide chassis warranty (Dongfeng), lifetime upfit service, spare parts dispatchable within 24 hours. Based on local procurement practice, the target unit price was approximately RMB 344,000, with total budget capped at RMB 1.5 million. II. Key Bidders Three enterprises participated in the tender: Chengli Special Automobile Co., Ltd., a Hubei-based special vehicle manufacturer, and a Shandong-based sanitation equipment enterprise. Their proposals are compared below: 1. Chengli Special Automobile Co., Ltd. Model Offered: CLW5070GSSD6 sewage treatment vehicle (based on Dongfeng 3308 mm wheelbase chassis). Key Configuration Highlights: • Chassis: National VI Dongfeng 3308 mm wheelbase, equipped with QuanChai 115 HP engine and engine pre-heating system; • Tank: 3 m³ stainless-steel tank with external thermal insulation layer and antifreeze circulation heating system; • Hydraulic System: Low-temperature-resistant sealing components; hydraulic oil viscosity rated for -35°C operation; • Solid-Liquid Separation: Screw-type extrusion separator, processing capacity ≥5 tons/hour; • After-sales Service: Dongfeng nationwide chassis warranty; lifetime upfit service; spare parts shipped within 24 hours. 2. Hubei-based Special Vehicle Manufacturer Model Offered: Vacuum truck conversion based on Dongfeng 3308 mm wheelbase chassis, but without dedicated freeze-protection design; standard hydraulic seals used. Unit price: ~RMB 321,000; after-sales coverage limited to chassis warranty only, with 1-year upfit warranty. 3. Shandong-based Sanitation Equipment Enterprise Model Offered: Based on Foton 3308 mm wheelbase chassis—significant parameter differences versus Dongfeng chassis, requiring additional modification announcement approval. Unit price: ~RMB 298,000; promised delivery lead time: 45 days; no service network in Northeast China. III. Comparative Summary of Strengths and Weaknesses Comparison Item Chengli Special Automobile Hubei-based Company Shandong-based Enterprise Chassis Model Dongfeng 3308 mm wheelbase, National VI Dongfeng 3308 mm wheelbase, National VI Foton 3308 mm wheelbase, National VI Freeze-Resistant Start Performance Equipped with pre-heating system; normal start-up at -30°C No pre-heating system; winter start-up unreliable