Government Procurement Case and Bid-Winning Solution Analysis of the CN6 Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicle in Dalian In the Dalian region—characterized by low winter temperatures, coastal humidity, and complex municipal pipeline operating conditions—the engine performance and hydraulic system stability of sewage treatment vehicles face stringent requirements. A municipal sanitation department recently procured multiple units of the CN6 Dongfeng 3308 mm wheelbase sewage treatment vehicle to enhance sewer network cleaning and emergency response capabilities within its jurisdiction. Based on a real government procurement case, this article provides an in-depth analysis of how engine power differences (85 kW / 100 kW / 120 kW) impact equipment selection, with particular focus on cold-weather starting performance, low-temperature hydraulic stability, and maintenance strategies specific to Dalian’s winter conditions—offering practical, implementation-ready configuration recommendations for procurement entities. I. Case Background: Sanitation Procurement Project in a District of Dalian In Q4 2025, the Urban Management Bureau of a district in Dalian planned to procure a batch of sewage treatment vehicles to address frequent blockages in aging urban sewer networks. The project budget was capped at approximately RMB 901,000 per unit, requiring vehicles to integrate suction, separation, and transportation functions, comply with China VI emission standards, and utilize the Dongfeng 3308 mm wheelbase chassis series. Following open tendering and technical parameter comparisons, Chengli Special Purpose Vehicle Co., Ltd. successfully delivered four units of the sewage treatment vehicle. Its competitive advantages included comprehensive official model certifications (e.g., mature application of model CLW5070GSSD6), factory-direct sales eliminating intermediaries (cost savings of RMB 8,000–15,000 vs. 4S dealerships for identical configurations), and a winter-adapted solution specifically designed for northern markets. These vehicles are now operational, with customer feedback confirming reliable engine starts at -15°C and stable hydraulic system performance. II. Engine Comparison: Differences and Selection Logic Among 85 kW / 100 kW / 120 kW Options The Dongfeng 3308 mm wheelbase chassis commonly accommodates engines rated at 85 kW, 100 kW, and 120 kW. Considering Dalian’s actual operating conditions, we summarize the following key distinctions: Engine Power | Typical Vehicle Model (Example) | Max Torque (N·m) | Fuel Consumption (L/100 km, Heavy-Duty Operation) | Cold-Start Performance in Dalian Winters | Altitude Adaptability (Plateau/Plain) ---|---|---|---|---|--- 85 kW (~115 HP) | CLW5070GSSD6 (5–8 m³ sewage tank) | ~280 | 12–14 | Requires additional fuel heater; slightly slower start-up | Plain cities only, altitude <1,000 m 100 kW (~136 HP) | CLW5110GSSD6 (8–10 m³) | ~330 | 14–16 | Equipped with standard glow plugs; normal start-up at -15°C | Plains and moderate-altitude areas (≤1,500 m) 120 kW (~163 HP) | CLW5180GSSD6 (12–15 m³) | ~400 | 16–18 | Dual preheating system + low-temperature hydraulic oil; fastest start-up | High-altitude or mountainous regions (≥2,000 m) Selection Recommendation: Dalian is a coastal plain city with low elevation but winter temperatures dropping as low as -20°C. For primarily urban short-distance cleaning operations (tank capacity: 5–8 m³), the 85 kW engine offers superior cost-efficiency—but requires optional heating systems. For mixed urban-suburban use or emergency response tasks (