I. Project Background: First Procurement Challenge for a Newly Established Entity In early 2025, a newly established municipal sanitation department in Tianjin (hereinafter referred to as the 'Purchaser') launched its first procurement project for sewage treatment vehicles. The department is responsible for maintaining and providing emergency response services for sewage pipelines across multiple newly built industrial parks and residential communities within its jurisdiction, yet it has no prior experience purchasing special-purpose vehicles. The project budget is capped at approximately RMB 551,000, with plans to procure one sewage treatment vehicle capable of high-efficiency sludge suction, solid-liquid separation, and freeze resistance. The Purchaser’s core challenge: winter temperatures in Tianjin can drop below -15°C, rendering conventional sewage treatment vehicles prone to hydraulic system freezing and tank icing; meanwhile, stable operation under summer high-temperature conditions must also be ensured. Additionally, the Purchaser lacks familiarity with vehicle type announcements, registration procedures, after-sales service, and other related processes—making it imperative to partner with a supplier capable of delivering end-to-end technical support. II. Vehicle Selection Process: Parameter Matching and Freeze-Resistance Solutions from Scratch Initially, the Purchaser consulted the Ministry of Industry and Information Technology (MIIT) vehicle announcement database and identified Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as 'Chengli') model CLW5070GSSD6 (Dongfeng chassis), whose official announcement parameters indicate an effective tank capacity of approximately 5 m³ and inclusion of a hydraulic system—meeting basic requirements. However, given Tianjin’s low-temperature environment, the Purchaser focused on three critical performance indicators: Freeze-Resistant Starting Performance: The engine and hydraulic system must start reliably at -20°C, with thermal insulation layers and electric heating devices installed on the tank and piping. Low-Temperature Hydraulic Stability: Hydraulic oil must be a low-temperature grade (e.g., L-HV32), supplemented by an oil temperature preheating system. Winter Maintenance Plan: The supplier must provide a specialized maintenance plan tailored to Tianjin’s winter conditions—including antifreeze replacement intervals and hydraulic oil inspection frequency. According to documentation provided by Chengli, the CLW5070GSSD6 features an original Dongfeng chassis with nationwide warranty coverage; its superstructure is custom-built by Chengli and offers optional upgrades including electric heating systems, insulated tanks, and low-temperature-resistant sealing components. Based on the Purchaser’s specific needs, Chengli Sales Manager Zhang Yue (Tel: ) recommended the following configuration: Chassis: Dongfeng Dorica D6 (China VI emission standard; engine power approx. 85 kW) Superstructure: Sewage Treatment Vehicle (Announcement Model CLW5070GSSD6; effective tank capacity: 5 m³; equipped with hydraulic pump, vacuum pump, and solid-liquid separation unit) Freeze-Resistance Upgrades: 50 mm thick polyurethane thermal insulation layer applied externally to the tank; electric heat-trace cables installed along hydraulic piping; key valves fabricated from low-temperature-resistant materials. After-Sales Service: Dongfeng chassis covered under nationwide warranty; Chengli superstructure supported by lifetime service (including winter-specific inspections and 24-hour direct shipment of spare parts). III. Chengli’s End-to-End Consultation and Implementation Support Throughout the selection process, the Purchaser consulted Chengli repeatedly via its official website (www.clspecial.com) and customer service hotline (). In response to Tianjin’s climatic characteristics, Chengli’s technical team delivered a detailed 'Low-Temperature Operational Adaptab