Background: Outdated sludge suction equipment — a bottleneck constraining municipal operational efficiency. In early 2025, a municipal sanitation department in Qingdao identified severe siltation in multiple drainage pipelines across its jurisdiction during routine inspections. During rainy seasons, this led to recurrent urban flooding risks. The existing sludge suction trucks were outdated 10-ton yellow-license-plate models — bulky, unable to access old residential communities and narrow streets, and hampered by low emission standards and scarce spare parts, resulting in an operational readiness rate of less than 70%. Compounding the issue, yellow-license-plate vehicles face city-center driving restrictions, forcing detours during operations; a single sludge removal task often took over half a day. The department head stated: “We urgently need a batch of highly maneuverable, blue-license-plate-compliant, and cost-effective compact sludge suction trucks — prioritizing clearance of back alleys and community pipeline networks.” Following internal evaluation, the procurement budget was capped at approximately RMB 1.358 million, with plans to acquire four blue-license-plate, 5-cubic-meter sludge suction trucks — each with a target budget of around RMB 339,000 (based on publicly available tender information). The vehicle specification explicitly required a Dongfeng single-cab chassis to ensure optimal driver visibility and operational convenience. Selection Research: Why the Dongfeng Single-Cab Blue-License-Plate 5-cubic-meter Model? Prior to launching the formal tender process, the department’s technical team benchmarked mainstream sludge suction truck models available on the market. The blue-license-plate 5-cubic-meter model was prioritized due to the following advantages: • Blue-license-plate accessibility: Operable with a Class C1 driver’s license, exempt from urban driving restrictions, enabling direct access to residential communities, industrial parks, and urban villages with narrow roads. • Dongfeng single-cab chassis: Spacious cab with excellent visibility; Dongfeng chassis enjoy high local market penetration in Qingdao, supported by abundant service centers and timely spare-part supply. • 5-cubic-meter capacity: Single-load capacity of approx. 3–5 tons of sludge — sufficient for routine maintenance while maintaining superior maneuverability without compromising road access. In terms of technical specifications, the team focused on the CLW5070GSSD6 model (Dongfeng chassis, 5-cubic-meter tank), requiring integrated high-pressure cleaning equipment, corrosion-resistant tank construction, and a hydraulic lifting system. Chengli’s Solution Match: End-to-End Service — From Technical Specifications to Delivery Following multiple rounds of technical discussions and live product demonstrations, the proposal from Chengli Special Purpose Vehicle Co., Ltd. stood out. Based on the Dongfeng single-cab blue-license-plate chassis, the upfit features a high-strength steel welded tank and includes the following core configurations: • Tank capacity: 5 cubic meters, with effective volume ≥ 4.8 m³ — meeting per-operation workload requirements. • High-pressure cleaning system: Equipped with an imported high-pressure pump delivering up to 20 MPa pressure — capable of clearing pipes up to 300 mm in diameter. • Hydraulic lifting & rear cover: Dual hydraulic cylinders for lifting; hydraulic locking mechanism for rear cover — ensuring safe, leak-free unloading. • Full regulatory compliance: This model is listed in the Ministry of Industry and Information Technology (MIIT) Announcement (reference series CLW5070GSSD6), enabling nationwide registration and annual inspection without local restrictions. In commercial negotiations, Chengli Sales Manager Zhang Yue (Tel: +86 ) provided a detailed configuration list and quotation, confirming: “Factory-direct sales — no intermediaries; same-specification pricing is RMB 8,000–15,000 lower th