I. Scenario Introduction: Real Procurement Demand for Sanitation Service Vehicles in a District of Guilin City, Guangxi In August 2025, a municipal sanitation department in Guilin launched a public tender for one Ford Transit V362 service vehicle, with a budget capped at approximately RMB 284,000. This procurement was not impulsive—increasingly severe emissions violations from aging diesel vehicles, coupled with severe corrosion of conventional models under South China’s hot-humid climate, created an urgent need for a service vehicle capable of high-frequency operation, corrosion resistance, and compliance with China VI emission standards. After multiple rounds of evaluation, Chengli Special Purpose Vehicle Co., Ltd. secured the contract with its China VI-compliant solution and localized service advantages, delivering this vehicle. According to publicly available tender information, the vehicle unit price was approximately RMB 248,000, covering chassis, body-upfitting, and standard configurations. Customer feedback noted: “The vehicle demonstrated stable performance during high-frequency operations in the rainy season, with no seal leakage observed.” This reliability stems from Chengli’s environment-specific design for South China, including anti-corrosion coatings and enhanced durability of sealing components optimized for hot-humid conditions. II. China VI Transition Policy and Phased Retirement Timeline for Older Vehicles Since the nationwide full implementation of China VI emission standards in 2021, numerous regions have accelerated the phase-out of China III and older vehicles. As a major tourist city, Guilin enforces stricter environmental requirements: By end-2023: Completion of phasing out China III and older diesel trucks By end-2025: Gradual restriction on China IV diesel trucks; incentives for upgrading to China VI vehicles As of 2026: China V vehicles face operational restrictions in certain areas, while China VI vehicles have become the mandatory standard in tenders. The Ford Transit V362 service vehicle procured herein features a China VI-compliant Ford 2.0T diesel engine (chassis), delivering 89 kW (121 hp) power and 300 N·m torque, meeting China VIb standards. This ensures seamless registration, annual inspection, and commercial operation nationwide without regulatory barriers. III. Chengli’s China VI Solution: Customized Design and Anti-Corrosion Coating To address Guilin’s hot-humid environment, Chengli implemented key optimizations: Anti-Corrosion Coating: Chassis and upfitted components utilize epoxy zinc-rich primer + polyurethane topcoat, achieving >1,000 hours in salt-spray testing—corrosion resistance improved 2–3× versus conventional processes. Sealing Component Durability: All doors, windows, cabinets, and pipeline interfaces employ fluororubber seals, rated for -40°C to +200°C, offering superior aging resistance compared to standard silicone rubber. High-Load Performance: Engine-transmission calibration and upgraded cooling systems are optimized for high-frequency rainy-season operations (e.g., daily mileage exceeding 200 km), ensuring uninterrupted performance. Interior customization per sanitation service requirements includes tool cabinets, first-aid kits, lighting systems, portable inspection equipment racks, and reserved 220V power outlets for external equipment. Customer feedback confirms: “No seal leakage occurred during continuous heavy-rain operations, and the anti-corrosion coating showed no blistering.” IV. Layered Subsidy Policies: From China VI Vehicle Purchase Incentives to Local Rewards The procuring entity reduced total cost through the following subsidy mechanisms: China VI Vehicle Purchase Subsidy: Per local procurement practice, China VI vehicles qualify for national subsidies for scrapping older vehicles (approximately RMB 10,000–20,000), with exact amounts varying by vehicle type and emission tier. Local Environmental Incentives: Guilin Municipality offers rewards of RMB 3,00