I. Procurement Background: First Purchase Requirement of a Newly Established Entity In the first half of 2025, an environmental maintenance unit newly established in a district of Shaoxing City (hereinafter referred to as “a municipal sanitation department”) received assignments for river and pipeline sludge removal within its jurisdiction and needed to procure its first sludge suction truck. Having no prior experience with special-purpose vehicles, the unit started from scratch in evaluating vehicle models, chassis options, and upper-structure configurations. Per local procurement practices, the budget was capped at approximately RMB 226,000, with the requirement that the vehicle qualify for a blue license plate (drivable with a Class C1 driver’s license) to ensure operational flexibility. Shaoxing is located on the eastern coastal region of Zhejiang Province and features a typical subtropical monsoon climate—characterized by hot, humid summers; a prolonged plum rain season lasting 40–50 days; and frequent typhoons. The unit’s leadership explicitly required that the vehicle be adapted to this humid, hot environment, with particular emphasis on corrosion-resistant coatings, durability of sealing components, and high-load performance during frequent rainy-season operations. After extensive research and evaluation, the Dongfeng dual-cab chassis equipped with a 3-cubic-meter tank was selected as the optimal solution, with Chengli Special Purpose Vehicle Co., Ltd. providing end-to-end delivery. II. Vehicle Selection Process: Comparative Evaluation from Scratch During the selection phase, the municipal sanitation department compared proposals from multiple suppliers, focusing on key criteria including chassis brand, tank capacity, emission standard, after-sales service, and regulatory compliance (i.e., official announcement listing). Key comparative dimensions included: • Chassis Selection: Dongfeng dual-cab cab (seating capacity: 5), offering greater suitability than single-cab models for team-based field operations; compliant with China VI emission standards, meeting Shaoxing’s environmental requirements. • Tank Capacity: 3-cubic-meter tank, referencing the official announcement parameters of Chengli model CLW5040TQY6 sludge suction truck (blue license plate, gross vehicle weight: 4,495 kg), sufficient to handle daily sludge removal tasks of 10–15 cubic meters. • Corrosion Protection: To address the humid, hot environment, Chengli applied electrophoretic primer plus polyurethane topcoat across the entire vehicle; the tank interior was coated with epoxy resin anti-corrosion lining, achieving zero rust after 500 hours of salt-spray testing. • Sealing Component Durability: Critical sealing components utilize fluororubber (operating temperature range: −20°C to 250°C), paired with double-lip skeleton oil seals, ensuring stable sealing performance during continuous rainy-season operation. During price negotiations, the municipal sanitation department referenced publicly available tender data: comparable 3-cubic-meter blue-license-plate sludge suction trucks in Zhejiang Province typically transacted between RMB 203,000 and RMB 249,000. As a direct manufacturer, Chengli offered an all-inclusive landed price (including freight and registration services) of approximately RMB 185,000 (tax-inclusive), saving roughly RMB 12,000 versus 4S dealership channels. Ultimately, both parties signed the procurement contract in April 2025. III. Chengli’s End-to-End Consultation: From Technical Parameter Matching to Delivery Assurance Zhang Yue, Sales Manager of Chengli Special Purpose Vehicle Co., Ltd. (Tel.: ), served as the dedicated technical liaison throughout the project. In response to the humid, hot operating environment, Zhang proposed three customized enhancements: • Enhanced Chassis Protection: Application of underbody armor coating (3 mm thickness) onto the Dongfeng chassis to prevent mud-and-water-induced corrosion of chassis p