I. Case Background: Sewage Treatment Vehicle Procurement Requirements in Baoding City A municipal sanitation department in Baoding City (hereinafter referred to as the "procuring entity") recently issued a public tender for a batch of National VI Dongfeng 3308 mm wheelbase sewage treatment vehicles, addressing urban sewer network maintenance and emergency response needs. According to the tender announcement, the procuring entity required vehicles capable of high-efficiency vacuum suction, solid-liquid separation, and remote discharge, and specified suitability for mixed terrain conditions—including plains and hills—in Baoding and surrounding areas. The total procurement budget was capped at approximately RMB 2.298 million, with around five units to be delivered, each priced at roughly RMB 400,000 (based on publicly available tender information). Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as "Chengli")—leveraging its mature sewage treatment vehicle product line and nationwide warranty service network—successfully delivered this batch of vehicles. These units are now operational across multiple streets and industrial zones in Baoding City, with customers reporting that operational stability and fuel consumption performance meet expectations. II. Engine Comparison Analysis: Differences and Selection Logic Among 85 kW / 100 kW / 120 kW Options The procuring entity explicitly stipulated in the tender technical specifications that engine power must range between 85 kW and 120 kW to accommodate varying operational intensities. Chengli’s National VI Dongfeng 3308 mm wheelbase sewage treatment vehicle chassis (e.g., derivative versions of model CLW5070GSSD6) supports three mainstream engine options, with key differences as follows: Engine Power 85 kW (~116 hp) 100 kW (~136 hp) 120 kW (~163 hp) Applicable Scenarios Urban light-load operations, short-distance transport, low-flow sewage suction Medium-load operations, mixed road conditions, routine tasks Heavy-load operations, long-distance transport, high-flow sewage suction Fuel Consumption (per 100 km, reference value) Approx. 12–14 L Approx. 14–16 L Approx. 16–19 L High-Altitude Adaptability (above 3,000 m elevation) Power loss ~15%; frequent gear downshifting required Power loss ~10%; normal operation maintained Power loss ~5%; minimal impact on efficiency Plain-Terrain Operational Efficiency Meets basic requirements but exhibits weak hill-climbing capability Balanced overall performance; recommended as primary choice Abundant power reserve, suitable for continuous high-intensity operations Annual Maintenance Cost (estimated) Lower Moderate Higher (due to increased component costs) Given the procuring entity’s actual requirements—vehicles primarily deployed for sewer network maintenance within Baoding City and neighboring counties, with daily medium-load operations and occasional emergency drainage during heavy rain—Chengli’s technical team recommended prioritizing the 100 kW engine variant, achieving optimal balance between fuel economy and power output. If budget permits and operational intensity is consistently high, the 120 kW variant offers greater performance redundancy. Ultimately, the procuring entity adopted the 100 kW solution, with each unit priced at approximately RMB 420,000 (based on publicly available tender information). III. Fuel Consumption Comparison and Cost Analysis Taking daily operations in Baoding City as an example, assuming each vehicle travels 100 km per day and operates for 8 hours: annual fuel cost for the 85 kW version is estimated at RMB 36,000–42,000; for the 100 kW version, RMB 42,000–48,000; and for the 120 kW version, RMB 48,000–57,000 (calculated based on current diesel prices).