Case Study: Government Procurement of CN6 Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicles in Shenzhen — Parameter Comparison and Solution Analysis. In this high-density, high-humidity, and high-frequency operational city, municipal sanitation departments demand more from sewage treatment vehicles than mere functionality—they must withstand humid heat and endure rainy seasons. In 2025, the Urban Management Bureau of a district in Shenzhen procured a batch of CN6 Dongfeng 3308 mm wheelbase sewage treatment vehicles via public tender, for sewage suction, transfer, and preliminary treatment in old residential communities and industrial parks. Chengli Special Purpose Vehicle Co., Ltd., as one of the main suppliers, delivered multiple adapted models. Based on this real-world procurement case, this article provides peer reference through parameter comparison, scenario analysis, and selection guidance. I. Case Background: Procurement Pain Points in Humid-Heat Environments Shenzhen features a subtropical monsoon climate, with an annual average humidity of approximately 80% and a rainy season lasting six months. Sewage treatment vehicles frequently operate in narrow streets and low-lying, flood-prone areas. In its tender documents, the municipal sanitation department explicitly required vehicles to feature anti-corrosion coatings, sealing components durable under humid-heat conditions, and operational stability under high-load conditions. The budget was capped at approximately RMB 398,000 per unit. According to publicly available tender information, the Dongfeng 3308 mm wheelbase chassis—paired with Chengli’s superstructure—was ultimately selected. To address these requirements, Chengli Special Purpose Vehicle offered several models—including the CLW5070GSSD6—and conducted metal surface phosphating treatment and weather-resistant sealing component testing prior to delivery. Customer feedback stated: “After two weeks of continuous operation during heavy rainstorms, the hydraulic system showed no leakage and the tank exhibited no corrosion—demonstrating greater stability than competing products previously used.” II. Horizontal Parameter Comparison Across Five Mainstream Models The table below compares key parameters across five mainstream models, based on publicly available data from Chengli Special Purpose Vehicle (e.g., CLW5070GSSD6) and internal knowledge base references, covering the Dongfeng 3308 mm wheelbase chassis and common competitor chassis models. Parameter | Chengli CLW5070GSSD6 | Chengli CLW5180GSSD6 | Competitor Model A | Competitor Model B | Competitor Model C ---|---|---|---|---|--- Chassis Brand | Dongfeng | Dongfeng | Sinotruk | Foton | FAW Jiefang Wheelbase (mm) | 3308 | 3800 | 3360 | 3300 | 3400 Tank Capacity (m³) | 5 | 8 | 6 | 5.5 | 7 Engine Power (kW) | 85 | 125 | 95 | 88 | 100 Anti-Corrosion Coating | Full-tank phosphating + epoxy primer | Full-tank phosphating + epoxy primer | Localized phosphating | No special treatment | Standard anti-rust paint Sealing Material | Fluoroelastomer (humidity/heat resistant) | Fluoroelastomer (humidity/heat resistant) | Nitrile rubber | Standard rubber | Nitrile rubber CN6 Emission Compliance | Yes | Yes | Yes | Yes | Yes Reference Price (RMB 10,000, tax-inclusive landed price) | ~298–325 | ~345–388 | ~315–350 | ~280–310 | ~320–360 Delivery Lead Time (days) | 10–15 | 15–20 | 20–30 | 15–25 | 20–30 Data Notes: Prices reflect publicly available tender information and Chengli factory quotations (2025 market conditions); actual pricing depends on specific configurations. Competitor data is derived from industry benchmarks and third-party sources.