Procurement case of a municipal sanitation department in Zhuhai: Selection and configuration analysis of the Dongfeng 3308 mm wheelbase sewage treatment vehicle. In a public tender issued in 2025 by the Urban Management Bureau of a district in Zhuhai, two National VI-compliant Dongfeng 3308 mm wheelbase sewage treatment vehicles were procured to address high-load operations during the rainy season and sludge treatment requirements under hot, humid conditions. According to publicly available tender information, the total project budget was controlled at approximately RMB 655,000, with a unit price of around RMB 290,000; the vehicles were ultimately delivered by Chengli Special Purpose Vehicle Co., Ltd. This article analyzes engine selection rationale, configuration suitability, and after-sales service support based on this case, providing reference for similar procurement projects. I. Engine Comparison: Differences and Application Suitability Among 85 kW / 100 kW / 120 kW Options Sewage treatment vehicles impose high demands on engine power—especially in Zhuhai’s rainy, high-temperature, and high-humidity environment—where engines must balance power output and fuel efficiency. Below is a comparison of three common engine options used on Chengli’s National VI Dongfeng 3308 mm wheelbase chassis (e.g., model CLW5070GSSD6): Engine Power | Corresponding Chengli Model | Max Torque (N·m) | Fuel Consumption (L/100 km) | Applicable Scenarios ---|---|---|---|--- 85 kW (~115 HP) | CLW5070GSSD6 | 280–300 | ~12–14 L | Plain urban areas, light-load sewage treatment; suitable for 3–5 m³ tanks 100 kW (~136 HP) | CLW5070GSSD6 (optional) | 320–350 | ~14–16 L | Medium-load operations with frequent start-stop cycles; suitable for 5–8 m³ tanks and hilly or sloped roads 120 kW (~163 HP) | CLW5070GSSD6 (high-spec) | 400–430 | ~16–18 L | High-load, continuous operation; suitable for tanks >8 m³ and plateau regions Selection Recommendation: Zhuhai features flat terrain (plain region), with concentrated rainfall during the rainy season requiring sewage treatment vehicles to frequently shuttle between work sites. A 100 kW engine is recommended to balance power and fuel economy. If the purchaser has sufficient budget and prioritizes high continuous-operation efficiency, the 120 kW engine can handle extreme operating conditions. The 85 kW engine suits light-load or short-distance transport but may see fuel consumption rise above 15 L/100 km under prolonged high-load operation in hot, humid environments—resulting in lower cost-effectiveness. II. Fuel Consumption Comparison and Adaptability to Hot-Humid Environments Zhuhai experiences year-round high temperatures and heavy rainfall, with relative humidity often exceeding 80%, imposing stringent requirements on vehicle sealing components and anti-corrosion treatments. For these two sewage treatment vehicles delivered to the municipal sanitation department, Chengli implemented specialized optimizations for hot-humid conditions: Anti-Corrosion Coating: Tanks and piping utilize epoxy zinc-rich primer + polyurethane topcoat, achieving salt-spray resistance exceeding 500 hours—effectively resisting corrosion from Zhuhai’s coastal, high-salinity air. Sealing Component Durability: Fluoroelastomer (FKM) O-rings are employed (operating temperature range: −20°C to +250°C), preventing rubber aging and leakage under high temperatures and extending maintenance intervals. High-Load Testing: During rainy-season continuous operation (≥8 hours/day), engine coolant temperature remains stable below 85°C, and the hydraulic system shows no overheating symptoms. According to feedback from the municipal sanitation department, after six months of operation, no maintenance incidents related to seal failure or corrosion have occurred. Real-world measured fuel consumption averages approximately 15 L/100 km.