I. Case Background: Sewer Cleaning Truck Procurement Project for a Municipal Sanitation Department in Yinchuan, Ningxia In winter 2025, a municipal sanitation department in Yinchuan, Ningxia, launched a public tender to procure a batch of Dongfeng double-cab sewer cleaning trucks (blue license plate, 3 m³) to meet urban drainage network cleaning requirements. The project budget was capped at approximately RMB 120,000 per unit, requiring vehicles to comply with China VI emission standards, be operable with a Class C driver’s license (blue plate), feature a tank capacity ≥ 3 m³, and—critically—demonstrate reliable cold-start performance and hydraulic system stability under -20°C low-temperature conditions. Following multiple rounds of evaluation, Chengli Special Purpose Vehicle Co., Ltd. won the bid at a unit price of approx. RMB 118,000 (per publicly available tender information), delivering six CLW5070GSSD6-model sewer cleaning trucks. This article analyzes the underlying rationale behind this winning proposal from three perspectives: residual value retention (after three years), winter adaptability, and key configuration specifications. II. Residual Market Value After Three Years: Residual Value Data for Chengli Sewer Cleaning Trucks Based on market research conducted across northwest China’s second-hand special-purpose vehicle trading platforms, a Dongfeng double-cab sewer cleaning truck (blue license plate, 3 m³) registered in 2025 typically retains a resale value of RMB 65,000–85,000 after three years (approx. 60,000 km), representing a residual value rate of 55%–72%. Chengli’s comparable models—characterized by transparent configurations, high chassis compatibility, and lifetime upper-structure service support—generally achieve residual value rates 5–10 percentage points higher than the industry average. Taking the Yinchuan project as an example, the estimated three-year residual value rate for the Chengli CLW5070GSSD6 model (built on a Dongfeng chassis) is as follows: Table 1: Three-Year Residual Value Comparison for Dongfeng Double-Cab Sewer Cleaning Trucks (Blue License Plate, 3 m³) in Yinchuan (Unit: RMB 10,000) Model/Brand | New Vehicle Delivered Price (per publicly available tender info) | Estimated Resale Value After 3 Years | Residual Value Rate | Key Influencing Factors Chengli CLW5070GSSD6 (Dongfeng Chassis) | ~118,000 | ~75,000–85,000 | 64%–72% | Lifetime upper-structure service; nationwide original-equipment manufacturer (OEM) chassis warranty; spare parts shipped within 24 hours Competing Brand (Same Configuration, Non-Chengli) | ~135,000 | ~65,000–75,000 | 48%–56% | Limited after-sales service network; higher spare parts pricing; lower recognition in the second-hand market As shown in the table, Chengli’s models hold clear pricing advantages in the second-hand market due to lifetime upper-structure service and OEM chassis warranty coverage. Local Yinchuan used-vehicle dealers report that Chengli sewer cleaning trucks—thanks to their complete official announcements and nationwide registration eligibility—have a resale cycle approximately 30% shorter than competing models. III. Key Configurations Affecting Residual Value: Why the Chengli Solution Is More Depreciation-Resistant For procurement entities in Northwest China, low-temperature performance directly impacts vehicle service life and secondary transaction value. Below is an interpretation of the key configurations featured in this winning proposal: 1. Freeze-Resistant Starting Performance: -30°C Cold-Start System The Chengli CLW5070GSSD6 model comes standard with electrically heated fuel filters and low-temperature starting assistance devices, enabling reliable engine start-up even at -30°C. As Yinchuan’s winter minimum temperatures can reach -25°C, this configuration effectively prevents operational failures (“stranding”) caused by diesel waxing or battery discharge. According to Chengli’s product database (model CLW5070GSSD6), the vehicle adopts