Government Procurement Case of Dongfeng Yizhan-Style Sewage Treatment Vehicle in Shenyang: An Efficient Solution for Low-Temperature Environments. In Northeast China, winter temperatures frequently drop to -30°C, imposing stringent requirements on specialized vehicles’ freeze-resistant starting capability and hydraulic system stability. This article takes the actual procurement case of a Dongfeng Yizhan-style sewage treatment vehicle by a municipal sanitation department in Shenyang as its entry point, providing a detailed analysis of the entire process—from trial use and evaluation to bulk procurement—to assist purchasing entities in making more scientific decisions for similar projects. I. Project Background and Procurement Requirements: By the end of 2025, the Urban Management Bureau of a district in Shenyang planned to procure a batch of sewage treatment vehicles due to increased maintenance demands on local sewage pipelines. According to publicly released tender information, the project budget was capped at approximately RMB 1.342 million, with three units scheduled for procurement. The vehicles were required to integrate suction, separation, and discharge functions, and must operate reliably under Shenyang’s extreme winter low-temperature conditions. Key procurement concerns included: Freeze-resistant starting performance: Whether the vehicle could start normally at temperatures ranging from -20°C to -30°C. Low-temperature hydraulic stability: Whether the hydraulic system exhibited leakage or sluggish operation under cold conditions. Winter maintenance support: Whether the manufacturer could provide targeted maintenance services. Following preliminary screening, the Dongfeng Yizhan-style sewage treatment vehicle offered by Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as “Chengli”) was shortlisted. As one of China’s largest special-purpose vehicle manufacturers, Chengli maintains a product database of 946 models across 44 categories, with extensive experience spanning numerous sanitation projects nationwide. II. Trial Use First: Validate Performance with One Unit Given Shenyang’s unique climatic conditions, the procuring entity adopted a ‘trial-use-first’ strategy: initially purchasing one Chengli Dongfeng Yizhan-style sewage treatment vehicle for a one-month field test before deciding on bulk procurement. The trial unit was based on the CLW5180GSSD6 chassis, equipped with a Tier VI emission-compliant engine, and fitted with Chengli’s proprietary sewage separation system. The trial period was scheduled for January 2026—the coldest month in Shenyang. Chengli Sales Manager Zhang Yue (Tel: ) provided full technical support throughout commissioning and delivered comprehensive winter maintenance guidance. Trial Performance Summary: Freeze-Resistant Starting Test: The vehicle successfully started on the first attempt for seven consecutive days during early-morning operations at -25°C, with no issues observed regarding oil freezing or battery discharge. Hydraulic System Stability: The hydraulic arm of the sewage separation unit operated smoothly under low temperatures—no leakage or jamming occurred, and hydraulic oil temperature reached normal operating range within 15 minutes. Operational Efficiency: A single suction operation (approx. 3 m³ capacity) took 12 minutes; separation efficiency exceeded 95%, fully meeting routine maintenance requirements. Winter Maintenance Feedback: Chengli provided complimentary antifreeze fluid replacement and installation of low-temperature engine pre-heaters, and committed to lifelong after-sales support for the upper-body assembly, with spare parts shipped within 24 hours. The on-site procurement representative stated: 'After one month of trial use, the vehicle demonstrated stable performance under low-temperature conditions—no unexpected breakdowns (“stranding”) occurred, and the proposed winter maintenance plan was also highly effective.' III. Comparative Analy