I. Case Background: Sewage Suction Truck Procurement Project of a Municipal Sanitation Department in Changde City. In the second half of 2025, a municipal sanitation department in Changde City, Hunan Province, planned to procure a batch of compact sewage suction trucks due to increased demand for cleaning urban drainage pipelines. Preliminary research indicated that the department specified requirements including: Dongfeng dual-cab chassis, blue license plate (drivable with Class C1 driver’s license), and 3-cubic-meter tank capacity—primarily for pipe unclogging and sludge removal in old residential communities and narrow alleys. The project budget was controlled at approximately RMB 227,000 (per publicly available tender information), with plans to procure two units at around RMB 100,000 per unit (based on local procurement practices). Such 'light-duty municipal' operating conditions impose three core requirements on vehicles: (1) Blue license plate compliance—enabling operation by drivers holding only a Class C1 license, thereby reducing labor costs; (2) Dual-cab configuration—accommodating 3–4 crew members; and (3) 3-cubic-meter tank capacity—sufficient to meet single-operation demands and minimizing frequent trips for unloading. Chengli Special Purpose Vehicle Co., Ltd. responded to these requirements with a dual-cab sewage suction truck solution built on a Dongfeng chassis. Two units were successfully delivered and are now operational across Changde City. Customer feedback highlights excellent maneuverability and high operational efficiency. II. Application-Matched Vehicle Selection Analysis: Light-Duty Municipal vs. Heavy-Duty Industrial vs. Specialized Operations Significant differences exist among operating conditions regarding chassis specifications, tank capacity, and functional configurations for sewage suction trucks. Below is an analysis of recommended parameters for three typical application scenarios, assisting procurement entities in precise vehicle selection. 1. Light-Duty Municipal Applications (e.g., Changde Project) Applicable Scenarios: Urban streets, residential neighborhoods, narrow alleys, and drainage ditches—characterized by narrow roads, small turning radii, and frequent entry/exit requirements. Recommended Specifications: Blue license plate; gross vehicle weight ≤ 4.5 tons; tank capacity 3–5 cubic meters; dual-cab configuration (seating up to 5 persons); Dongfeng chassis (e.g., CLW5070GSSD6 series modifications). Key Configurations: Hydraulic sewage suction pump, high-pressure flushing gun, self-dumping function, and corrosion-resistant tank lining. Engine power: ~95–110 HP, compliant with urban speed limits and environmental regulations. 2. Heavy-Duty Industrial Applications Applicable Scenarios: Industrial parks, mining sites, large construction sites—where sludge contains abundant sand and gravel, exhibits high density, and demands intensive operations. Recommended Specifications: Yellow license plate; gross vehicle weight 8–12 tons; tank capacity 6–10 cubic meters; single-cab or cab-and-a-half configuration; heavy-duty chassis (e.g., Sinotruk or FAW). Requires reinforced tank structure, high-flow hydraulic pump, and heavy-duty self-dumping system. Reference Case: A Guangdong industrial park procured five Chengli water-sprinkling trucks and misting cannon trucks, including heavy-duty sewage suction equipment, for coordinated dust suppression and environmental control. 3. Specialized Emergency Operations Applicable Scenarios: Disaster relief, tunnel/culvert clearance, riverbed dredging—requiring exceptional maneuverability, deep-water fording capability, and emergency-specific functions. Recommended Specifications: Four-wheel drive (4WD) or all-wheel drive (AWD) chassis; specialized modifications; tank capacity 3–5 cubic meters; optional vacuum sewage suction functionality. For example, the Chengli CLW5070GSSD6 series can be equipped with dual systems combining high-pressure cleaning and vacuu