Government procurement case of the new Dongfeng sewage treatment vehicle in Yinchuan: The decision-making path from trialing one unit to bulk procurement. In winter 2025, a municipal sanitation department in Yinchuan faced an urgent challenge: outdated sewage treatment facilities in its jurisdiction suffered from low efficiency, frequent pipeline freezing, and equipment startup difficulties under low winter temperatures. Following local procurement practices, the department planned to procure a batch of new sewage treatment vehicles—with the critical requirement that they must operate reliably in Yinchuan’s harsh winter conditions, where temperatures routinely drop below -20°C. After extensive evaluation, the new Dongfeng sewage treatment vehicle (model reference: CLW5070GSSD6 chassis-modified) supplied by Chengli Special Purpose Vehicle Co., Ltd. emerged as a top candidate. Unlike conventional tendering procedures, the department adopted a 'trial-first' strategy—procuring one unit for on-site testing before deciding on the scale of bulk procurement. I. Trial of One Unit: Real-World Winter Testing Initiated In November 2025, the municipal sanitation department of Yinchuan City entered into a trial agreement with Chengli Special Purpose Vehicle Co., Ltd. One new Dongfeng sewage treatment vehicle—based on the Dongfeng Dorica chassis and compliant with China VI emission standards—was delivered to a sewage treatment station in Yinchuan. The trial period was set at 45 days, focusing on three core performance indicators: • Cold-weather startup reliability: Whether the vehicle could start successfully on the first attempt during early-morning temperatures ranging from -15°C to -20°C; • Low-temperature hydraulic system stability: Whether the hydraulic system exhibited oil solidification, pipeline leakage, or sluggish actuation under sub-zero conditions; • Winter maintenance support: Whether Chengli’s after-sales team could provide timely services such as antifreeze fluid replacement and battery insulation. According to Chengli’s product database, this model is equipped with Dongfeng’s original factory cold-weather kit, plus Chengli’s proprietary 'Low-Temperature Startup System', including a fuel heater and battery insulation cover. During actual testing, the vehicle achieved successful first-start ignition for seven consecutive early-morning trials at sub-zero temperatures; the hydraulic system maintained stable pressure even at -18°C, with no observable performance degradation. This performance significantly surpassed that of comparable models on the market—the department had previously trialed a competing brand’s sewage treatment vehicle, which experienced hydraulic oil thickening and actuator jamming at just -12°C. II. Trial Performance Record: Data-Driven Evaluation During the trial period, the Yinchuan municipal sanitation department collected detailed operational data and cross-verified it against official parameters published in Chengli’s product database (e.g., model CLW5070GSSD6). Key monitoring results are summarized below: Yinchuan New Dongfeng Sewage Treatment Vehicle Winter Trial Performance Comparison Table Test Item | Chengli Dongfeng Sewage Treatment Vehicle | Competitor A (Same Chassis Type) | Competitor B (Other Brand) Minimum Startup Temperature | -22°C (successful first-start) | -12°C (requires 10-min preheating) | -15°C (occasional startup failure) Hydraulic System Stability at Low Temp | Normal operation at -18°C, no leakage | Hydraulic oil thickens at -12°C, sluggish response | Seal failure at -15°C, requiring replacement Average Daily Sewage Processing Capacity | ~80 m³ (based on local operating conditions) | ~65 m³ | ~70 m³ Fuel Consumption (per 100 km) | 12.5 L (China VI standard) | 13.8 L | 13.2 L After-Sales Response Time | 24 hours (Chengli Ningxia Service Station) | 48 hours (dispatch required from out-o