I. Project Background and Core Requirements A municipal sanitation department in Anshan launched a procurement project for Dongfeng Yizhan-style sewage treatment vehicles at the end of 2025, with a budget controlled within approximately RMB 900,000–1,351,000 (per publicly available tender information). The region experiences severe winter cold, with minimum temperatures reaching -25°C; additionally, some operational areas are located in aging urban districts and suburban zones featuring narrow roads and bridges with limited load-bearing capacity. The procuring entity prioritized three core requirements: frost-proof starting performance (ensuring uninterrupted operation during early-morning winter shifts), low-temperature hydraulic system stability (preventing hydraulic oil solidification and consequent pump failure), and winter maintenance solutions (reducing maintenance costs and downtime risks). After multiple rounds of evaluation, Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as "Chengli") delivered four Dongfeng Yizhan-style sewage treatment vehicles. The chassis selected was the Dongfeng Tianjin series, while the superstructure featured Chengli’s independently developed sewage treatment system. Below is an in-depth analysis across three dimensions: chassis selection, load-bearing capacity & maneuverability, and maintenance convenience. II. Chassis Selection Comparison: Differentiated Analysis of Dongfeng / Sinotruk / Foton / FAW In government procurement, chassis selection directly impacts vehicle registration, annual inspection, commercial operation, and after-sales service. Based on MIIT announcement parameters (e.g., model CLW5070GSSD6) and practical tender experience, the following compares four mainstream chassis types: Chassis Brand | Engine Type | Max Power (kW) | Drive Configuration | Wheelbase (mm) | Typical Application | Frost-Proof Performance | Maintenance Convenience ---|---|---|---|---|---|--- Dongfeng (e.g., Tianjin / Dolicar) | Yuchai / Cummins diesel engines | 160–210 | 4×2 | 3,800–4,500 | Urban sanitation, medium/short-haul transport | Standard preheating system enables cold start down to -35°C | Nationwide warranty network; dense service station coverage Sinotruk (e.g., Howo / Sitrak) | Weichai / MAN technology | 180–260 | 4×2 / 6×4 | 4,200–4,800 | Heavy-duty operations, complex road conditions | Optional independent heating system; higher fuel consumption | Strong service presence in northern cities, but slower response in remote areas Foton (e.g., Ouman / Oumaka) | Cummins / Yuchai | 150–220 | 4×2 | 3,600–4,500 | Light-duty, urban delivery | Standard electric heating; additional hydraulic system modifications required for extreme cold | Extensive service network, but specialized vehicle parts may require longer lead times FAW (e.g., J6L / LongV) | Xichai / Dachai | 160–230 | 4×2 / 6×4 | 4,000–4,700 | Long-haul transport, heavy-duty operations | Standard electric heating; higher fuel consumption | Numerous service stations across Northeast China, but relatively sparse coverage in southern regions Per publicly available tender information, the Anshan procuring entity ultimately selected Dongfeng chassis for three key reasons: outstanding frost-proof starting capability (standard preheating system combined with Chengli-installed low-temperature hydraulic oil tank ensures reliable startup at -30°C); optimal balance between load-bearing capacity and maneuverability (Dongfeng Tianjin chassis features moderate wheelbase and small turning radius, ideal for narrow streets in older urban districts); and superior maintenance convenience (more than five authorized Dongfeng service stations operate in Anshan and surrounding cities, and Chengli provides lifetime superstructure service with 24-hour direct shipment of spare parts). III. Load-Bearing Capacity and Maneuverability: Core Advantages of the Dongfeng Yizhan Model Sewage treatment vehicles must accommodate tanks, pump units, control