Interpretation of the Baotou Dongfeng D6 Blue-Plate Sewage Treatment Vehicle Government Procurement Case: Analysis of National VI Compliance and Cost Advantages In 2025, a municipal sanitation department in Baotou City, Inner Mongolia, publicly tendered for a batch of blue-plate sewage treatment vehicles as part of its urban drainage network upgrade project. Ultimately, Chengli Special Purpose Vehicle Co., Ltd. delivered three units of the CLW5070GSSD6 blue-plate sewage treatment vehicle built on the Dongfeng D6 chassis (essentially a modified water tanker with sewage treatment capability). The total procurement budget was controlled within approximately RMB 1.077 million, with an average unit contract price of around RMB 300,000 (based on publicly available tender information). This case illustrates how grassroots units achieve cost reduction and efficiency improvement through policy-compliant vehicle selection amid the nationwide implementation of the National VI emission standards. This article provides an interpretation from perspectives including policy background, vehicle solution, and subsidy synergies. I. National VI Policy Background and Phasing-Out Timeline for Older Vehicles Effective July 1, 2023, the National VIb emission standard was fully implemented nationwide; all newly registered special-purpose vehicles must comply with this standard. This policy has profoundly impacted the sanitation vehicle market: Phasing-Out Timeline for Older Vehicles: According to policies across multiple regions, diesel-powered vehicles meeting China III or lower emission standards must be fully phased out by the end of 2025; China IV vehicles face progressively stricter restrictions in key regions (e.g., Beijing-Tianjin-Hebei, Yangtze River Delta), with full phase-out expected before 2027; although China V vehicles remain operational, they encounter limitations during new registration and transfer procedures. Local Policy in Baotou: The city mandates that all newly purchased sanitation vehicles must meet at least the National VIb standard starting in 2025, and offers subsidies for early retirement of older vehicles (per local procurement practice, subsidies range from RMB 10,000 to RMB 30,000 per vehicle). Economic Considerations: Increased annual inspection frequency, rising maintenance costs, and expanding restricted driving zones compel municipal authorities to accelerate fleet renewal. Against this backdrop, the Baotou project explicitly required bidders to supply vehicles compliant with the National VIb standard, accompanied by complete MIIT (Ministry of Industry and Information Technology) announcement parameters. Chengli’s CLW5070GSSD6 model—mounted on the Dongfeng D6 chassis and powered by a Yuchai 140-horsepower engine meeting National VI standards—fully satisfied these requirements. II. Chengli’s National VI Solution: Technical Overview of the Dongfeng D6 Blue-Plate Sewage Treatment Vehicle The delivered vehicles were CLW5070GSSD6 water tankers modified by Chengli into sewage treatment vehicles, capable of sewage collection, transportation, and preliminary treatment. Based on technical specifications, core configurations include: Chassis Model: Dongfeng D6 series, wheelbase 3,308 mm, rated occupancy: 2 persons, gross vehicle weight rating (GVWR): 7.3 tons, curb weight approx. 3.5 tons. Tank Capacity: Approx. 5 m³, suitable for liquid sewage or sludge, meeting small-scale urban operation requirements. Emission Standard: National VIb, equipped with DOC + DPF + SCR after-treatment system, fully compliant with latest environmental regulations. Upper-Structure Features: Self-priming and self-discharging system; high-pressure cleaning equipment (for pipeline unclogging); tank fabricated from corrosion-resistant Q235 carbon steel, suitable for handling corrosive sewage. MIIT Announcement Status: Model CLW5070GSSD6 is listed in the MIIT Announcement, enabling normal registration, annual inspection, and commercial operatio