Government procurement case of National VI Dongfeng 3308 mm wheelbase sewage treatment vehicles in Taiyuan: Parameter comparison and selection solution interpretation. In winter municipal sanitation operations in northern cities, low-temperature engine starting and hydraulic system stability are the most critical pain points for procurement entities. In December 2025, a municipal sanitation department in Taiyuan City publicly procured a batch of National VI Dongfeng 3308 mm wheelbase sewage treatment vehicles to meet urban sewage pipeline maintenance requirements. The purchaser required reliable engine start-up at -15°C and no hydraulic system jamming under low-temperature conditions, while maintaining budget control within a reasonable range. Ultimately, Chengli Special Purpose Vehicle Co., Ltd. secured the order with a solution featuring precise parameter matching and winter-adapted design, successfully delivering five units. Below is a detailed case analysis of this procurement. I. Procurement Background and Core Requirements The department’s existing fleet had aged significantly, resulting in high failure rates during winter—severely impacting emergency pipeline clearance efficiency. This procurement emphasized three mandatory technical criteria: freeze-resistant starting performance (cold-start success rate ≥98% at -20°C), low-temperature hydraulic stability (hydraulic oil pour point ≤ -35°C), and a comprehensive winter maintenance plan (including antifreeze coolant and engine pre-heating systems). Per publicly released tender documents, the budget was capped at approximately RMB 280,000–336,000 per unit; the chassis was required to be Dongfeng with a 3308 mm wheelbase and National VI emission compliance, while the superstructure was to be supplied by a specialized manufacturer. II. Horizontal Parameter Comparison Across Five Mainstream Models To clearly illustrate configuration differences among competing models, we selected five currently available sewage treatment vehicles based on the Dongfeng 3308 mm wheelbase—including Chengli and competing brands—for comparative analysis. All data below are sourced from MIIT official announcements and manufacturers’ publicly disclosed specifications. The CLW5070GSSD6 model listed is an in-production Chengli vehicle. Model/Brand | Chassis Wheelbase (mm) | Engine Power (kW) | Tank Capacity (m³) | Hydraulic System Model | Low-Temperature Starting Assistance | Reference Price (RMB 10,000s) ---|---|---|---|---|---|--- Chengli CLW5070GSSD6 | 3308 | 95 | 5.2 | Dual-gear pump + solenoid valve bank | Diesel heater + electric preheating | ~26–29 Competitor A (Dongfeng OEM) | 3308 | 92 | 4.8 | Single-gear pump | Electric preheating only | ~28–32 Competitor B (Third-party upfitter) | 3308 | 88 | 5.0 | Manual directional control valve | None | ~24–27 Chengli CLW5070GQW6 (Upgraded version) | 3308 | 100 | 5.5 | Proportional servo valve | Diesel heater + electric preheating + low-temp hydraulic oil | ~30–34 Competitor C (Southern brand) | 3308 | 90 | 4.5 | Conventional hydraulic pump | None | ~22–25 Note: Prices reflect publicly available tender information and regional procurement practices; actual transaction prices may vary depending on configuration. III. Dimensional Comparative Analysis 1. Freeze-Resistant Starting Performance In Taiyuan’s winter, temperatures of -15°C are common. The Chengli CLW5070GSSD6 comes standard with both a diesel heater and electric preheating system, raising engine coolant temperature above 20°C prior to startup—ensuring reliable cold starts. In contrast, Competitor C offers no auxiliary starting features, resulting in a reported 30% cold-start failure rate under low-temperature conditions. According to the department’s field testing, the Chengli vehicle achieved a 100% single-attempt start success rate even at -18°C. 2.