I. Project Background: Sewage Treatment Challenges in Extreme Cold Environments In winter 2025, a municipal sanitation department in Qiqihar launched a public tender to upgrade aging sewage treatment infrastructure within its jurisdiction, seeking procurement of one yellow-plate sewage treatment vehicle (model 3308). The project specifically addresses operational inefficiencies and equipment freezing—such as hydraulic system cracking—under severe cold conditions (extreme low temperatures down to -35°C). Per the tender documents, the budget was capped at approximately RMB 392,000, with mandatory requirements including frost-resistant engine starting capability, hydraulic system stability at low temperatures, and compliance with China VI emission standards. Ultimately, Chengli Special Purpose Vehicle Co., Ltd. delivered a sewage treatment vehicle built on the CLW5070GSSD6 chassis. Its unit price was approximately RMB 328,000 (per publicly available tender information). The department reported: “In previous winters, our sewage vehicles frequently broke down due to hydraulic oil solidification and diesel waxing. During field testing, this Chengli vehicle demonstrated exceptional reliability—successfully cold-starting at -30°C and operating continuously without failure.” II. Core Requirements: Frost-Resistant Starting & Low-Temperature Hydraulic Stability Located at 47°N latitude, Qiqihar experiences long, bitterly cold winters. Conventional sewage treatment vehicles commonly face three critical issues under sub-zero conditions: • Diesel waxing: Standard No. 0 diesel begins forming wax crystals at -10°C, causing fuel line blockages. • Hydraulic system failure: Hydraulic oil viscosity surges dramatically, reducing pump efficiency by over 30%. • Battery power loss: Lead-acid batteries retain only ~50% of their rated capacity at -20°C. To address these challenges, Chengli Special Purpose Vehicle implemented targeted upgrades on the CLW5070GSSD6 model: • Standard water-circulation heating system utilizing engine coolant to preheat the fuel tank and hydraulic lines—ensuring reliable engine start-up within 5 minutes at -35°C. • Use of low-temperature hydraulic oil (ISO VG 32), with pour point lowered to -45°C, ensuring consistent hydraulic system performance. • Integration of cold-weather starting aids—including intake air preheaters and battery thermal insulation covers—as specified in Chengli’s After-Sales Service Manual. For customized solutions, contact Sales Manager Zhang Yue at +86 . III. Vehicle Configuration vs. Tender Requirements The tender attracted bids from three suppliers. Chengli’s awarded configuration is detailed below: | Configuration Item | Chengli CLW5070GSSD6 (Awarded Bid) | Competitor A (Unsuccessful) | Competitor B (Unsuccessful) | |-------------------|-------------------------------------|------------------------------|------------------------------| | Chassis Brand | Dongfeng Dorica | Sinotruk HOWO | Foton Oumanke | | Engine Power | 96 kW (China VI compliant) | 88 kW (China V compliant) | 100 kW (China VI compliant) | | Sewage Tank Capacity | 6.8 m³ | 6.5 m³ | 7.0 m³ | | Hydraulic System | Low-temperature specific (pour point: -45°C) | Standard hydraulic oil (pour point: -20°C) | Low-temperature type (pour point: -35°C) | | Frost-Resistant Starting System | Water-circulation heating + intake air preheater | Intake air preheater only | Electric oil pan heater | | After-Sales Service | Nationwide Dongfeng chassis warranty + lifetime upfit warranty | Chassis warranty only; upfit warranty: 2 years | Chassis warranty only; upfit warranty: 3 years | | Unit Price (per public tender data) | ~RMB 328,000 | ~RMB 345,000 | ~RMB 332,000 | As shown above, Chengli’s solution demonstrates clear superiority in low-temperature adaptability. Moreover, its after-sales policy—featuring nationwide Dongfeng chassis warranty plus lifetime upfit warranty—aligns precisely with Chengli’s official knowledge base statement: