Managerial Perspective: Fleet Management Director's Evaluation — During a recent visit to a municipal sanitation department in Tianshui City, Mr. Li (a pseudonym), the fleet management director, provided an objective assessment of three National VI Dongfeng 3308 mm wheelbase sewage treatment vehicles (model reference: CLW5070GSSD6) procured collectively last year. Mr. Li stated: 'These vehicles are primarily deployed for emergency cleaning and unclogging of aging urban sewer networks and septic tanks. Prior to procurement, we compared multiple brands and ultimately selected Chengli Special Purpose Vehicles, mainly due to their superior chassis–body integration and rapid after-sales service response.' According to Mr. Li, the department acquired these vehicles through public tendering in 2025, with a total budget capped at approximately RMB 905,000 (i.e., ~RMB 260,000 per unit, based on publicly available tender information). Following delivery, the vehicles underwent a one-month trial operation period and have now officially entered routine service. Mr. Li specifically noted: 'The vehicles supplied by Chengli fully comply with China’s National VI emission standards as certified under Chassis Announcement CLW5070GSSD6. Moreover, being locally manufactured in Suizhou, the order-to-delivery cycle took only about 12 days—nearly one week faster than anticipated.' Regarding overall vehicle performance, Mr. Li emphasized: 'Sewage treatment vehicles frequently operate in narrow residential neighborhoods and back alleys; the Dongfeng 3308 mm wheelbase chassis offers a small turning radius, delivering excellent maneuverability. Furthermore, Chengli provides transparent configuration options—no bundled pricing packages—allowing us to clearly identify the cost of each functional component during procurement, a rare advantage observed in previous tenders.' Operational Flexibility: Real-World Performance Under Complex Conditions — The municipal sanitation department oversees both historic urban districts and newly developed zones, where pipeline infrastructure is highly heterogeneous, demanding exceptional vehicle dispatch flexibility. Mr. Li shared a typical scenario: 'Once, we received an urgent assignment to clear a blocked main sewage pipe in the old city district. We dispatched one Chengli sewage treatment vehicle, which successfully navigated a 3.5-meter-wide alleyway and completed coupling and operations within the confined space—without disrupting local traffic.' Feedback indicates that the Chengli sewage treatment vehicle is equipped with a self-priming sewage pump and high-pressure cleaning system, enabling independent execution of suction, transport, and preliminary separation functions. Mr. Li commented: 'This integrated design significantly reduces the need for repeated vehicle dispatches. Previously, resolving a single blockage required coordinated deployment of both a vacuum tanker and a high-pressure cleaning truck; now, one vehicle suffices—greatly improving dispatch efficiency.' Additionally, the vehicle demonstrates stable performance under low winter temperatures. Mr. Li remarked: 'Tianshui’s winter temperatures occasionally drop to -10°C, yet the vehicle’s hydraulic system and piping show no freezing issues—thanks to freeze-resistant design features incorporated into both chassis and bodywork. Chengli’s configuration list explicitly details these anti-freeze measures, proving highly practical.' Fuel Consumption Monitoring Data: Economic Performance Analysis in Actual Operation — To evaluate economic efficiency, the department conducted a three-month fuel consumption monitoring campaign across all three Chengli sewage treatment vehicles. Statistical data revealed an average fuel consumption of approximately 13.5 L/100 km under mixed urban operating conditions—significantly lower than the department’s other comparable-brand vehicles (averaging ~15 L/100 km), demonstrating clear fuel-saving benefits. Mr. Li explained: