Kunming Government Procurement Case for China VI Dongfeng 3308 mm Wheelbase Sewage Treatment Truck: A Practical Analysis from Trial Use to Batch Procurement. In early 2025, a municipal sanitation department in Kunming (hereinafter referred to as 'the Department') faced an urgent challenge: long-term blockages in stormwater and sewage pipelines across multiple old residential communities, exacerbated by frequent rainy seasons, resulting in sewage overflow and odor nuisance to residents. Conventional vacuum suction trucks demonstrated low operational efficiency and were incapable of handling high-concentration sludge. Following preliminary research, the Department decided to procure a batch of sewage treatment trucks, with key evaluation criteria including corrosion resistance, durability of sealing components under hot-humid conditions, and stability during high-load operations in the rainy season. After comparing multiple brands, the Department selected the China VI Dongfeng 3308 mm wheelbase sewage treatment truck supplied by CLW Special Purpose Vehicle Co., Ltd. (hereinafter referred to as 'CLW') (model reference: CLW5070GSSD6 chassis specifications), adopting a 'trial-first' strategy: purchasing one unit for a three-month field test before deciding on bulk procurement. I. Trial Phase: One Vehicle, Three Months, 40 Operational Records In March 2025, one CLW Dongfeng 3308 mm wheelbase sewage treatment truck was officially delivered to the Department. Equipped with a China VI emission-compliant engine, the vehicle features a tank capacity of approximately 5 m³, a high-vacuum suction pump, and a solid-liquid separation system. During the trial period, the Department assigned dedicated personnel to record each operation, focusing on the following performance indicators: Corrosion Resistance Performance: Kunming’s climate features alternating dry and humid conditions, and the wastewater contains corrosive substances. The CLW vehicle’s tank undergoes full hot-dip galvanization, followed by external coating with epoxy zinc-rich primer and acrylic polyurethane topcoat. After three months, inspection revealed no rust at weld seams or flange connections; only minor surface oxidation was observed on a few bolts—significantly outperforming competing vehicles (e.g., a comparable model from another brand exhibited pitting corrosion after just two months). Sealing Component Durability: During the rainy season (June–August), the vehicle operated frequently, averaging four deployments per week. Critical sealing areas—including the rear tank lid gasket and suction pipeline joints—showed no leakage under continuous hot-humid conditions. In contrast, another brand’s vacuum suction truck used concurrently by the Department (in service for one year) already exhibited aging and cracking of rubber seals; CLW’s rubber components are projected to extend replacement intervals by over 30%. High-Load Operational Stability: Following a heavy rainstorm, the vehicle operated continuously for eight hours, processing approximately 40 tons of sewage and sludge. Engine coolant temperature and hydraulic system pressure remained within normal ranges throughout, and vacuum pump suction performance stayed stable without shutdowns or failures. Upon completion of the trial period, the Department issued a formal evaluation report stating: 'The CLW Dongfeng 3308 mm wheelbase sewage treatment truck meets Kunming’s rainy-season operational requirements in terms of corrosion resistance, sealing integrity, and continuous-duty capability—demonstrating overall performance superior to existing equipment.' II. Market Comparison: Why Is the CLW Solution Superior? During the trial phase, the Department concurrently evaluated three other domestic brands offering similar products (all based on Dongfeng chassis, ~5 m³ tank capacity). The comprehensive comparison results are summarized in the table below: Comparison Item | CLW Dongfeng 3308 mm Wheelbase Sewage Treat