I. Case Background: Sewage Treatment Vehicle Procurement Requirement of a Municipal Sanitation Department in Huizhou In early 2025, a municipal sanitation department in Huizhou City, Guangdong Province, issued a public tender for a batch of China VI emission-standard sewage treatment vehicles to address increasing pressure on sewage pipeline systems across local industrial parks and residential areas. According to the tender notice, the project budget was capped at approximately RMB 1.996 million, with plans to procure three sewage treatment vehicles built on the Dongfeng 3308 mm wheelbase chassis. Key requirements included a high-efficiency separation system, automatic sewage discharge functionality, and compliance with local environmental emission standards. Following multiple rounds of evaluation, Chengli Special Purpose Vehicle Co., Ltd. delivered three CLW5070GSSD6-type sewage treatment vehicles at a unit price of approximately RMB 550,000 (based on publicly available tender information). Since their commissioning in June 2025, customer feedback has highlighted stable treatment efficiency, low maintenance costs, and notably high residual value in the used-vehicle market. This case serves as the entry point for this article, which analyzes procurement selection logic from the perspective of residual value. II. Used-Vehicle Market Price After 3 Years: Residual Value Performance of Chengli Sewage Treatment Vehicles By industry convention, special-purpose vehicles—such as sewage treatment vehicles—typically enter the secondary market after 3–5 years of service. Their residual value is influenced by brand reputation, chassis quality, superstructure (upper assembly) reliability, and maintenance history. Taking the Dongfeng 3308 mm wheelbase sewage treatment vehicles delivered in this project as an example, and referencing the official announcement parameters for the CLW5070GSSD6 model in Chengli’s product database (curb weight approx. 4.5 tons; rated payload approx. 2.5 tons), combined with market research data: Residual value after 3 years: Approximately RMB 250,000–320,000, representing a residual value rate of 45%–58%. Comparison with peer competitors: Due to the use of original-equipment Dongfeng chassis (nationwide warranty) and lifetime after-sales support, Chengli models consistently command used-vehicle transaction prices approximately 10%–15% higher than non-branded alternatives. Key influencing factors: Vehicles with complete maintenance records, no major accidents, and fully functional superstructures can achieve resale prices near the upper end (approx. RMB 355,000); conversely, units exhibiting severe chassis or separation system aging may fall below RMB 250,000. This strong residual value performance aligns consistently with Chengli’s long-standing reputation established in other government procurement cases—e.g., 15 street sweepers supplied to Wuhan Municipal Urban Management Bureau, and five water-sprinkler trucks plus mist cannons delivered to an industrial park in Guangdong Province. Procuring entities frequently prioritize high-residual-value brands in subsequent tenders to reduce total cost of ownership over the vehicle lifecycle. III. Residual Value Comparison: Chengli Sewage Treatment Vehicles vs. Peer Competitors To clearly illustrate Chengli’s residual value advantage, the following table compares used-vehicle market prices after three years (in RMB ten-thousands), based on publicly disclosed government procurement data and industry research: | Model/Brand | Approx. New Purchase Price (per tender reference) | Used-Vehicle Price After 3 Years | Residual Value Rate | Key Differentiators | |-------------|---------------------------------------------------|----------------------------------|------------------------|----------------------| | Chengli CLW5070GSSD6 | ~RMB 550,000 | RMB 250,000–320,000 | 45%–58% | Original-equipment chassis with nationwide warranty; lifetime superstructure service; spare parts