A municipal sanitation department conducted a winter tender and procured a batch of National VI Dongfeng sewage treatment vehicles with a 3308 mm wheelbase to address urban sewage treatment and temporary drainage needs. After delivery, customers reported stable operation, especially outstanding performance under sub-zero conditions. This article analyzes vehicle maintenance essentials, cold-weather starting recommendations, freeze-protection measures, and the rationale behind the winning bid—based on this case study and from a winter operations perspective. I. Case Background: Analysis of Winter Procurement Requirements in Suzhou According to publicly available tender information, the municipal sanitation department launched its sewage treatment vehicle procurement project prior to winter, with a budget capped at approximately RMB 393,000. The tender required vehicles compliant with National VI emission standards and featuring a 3308 mm wheelbase to accommodate narrow urban road operations. Ultimately, Chengli Special Purpose Vehicle Co., Ltd.’s proposal won the bid, delivering five units of model CLW5070GSSD6 sewage treatment vehicles. Customer feedback confirmed reliable engine start-up even at -5°C and achieved expected sewage treatment efficiency. In this case, the procuring entity placed particular emphasis on operational reliability during winter, as low temperatures commonly cause diesel fuel gelling, reduced battery performance, and pipeline freezing. Chengli’s solution met these requirements through optimized chassis configuration and freeze-resistant upper-body design. II. Core Winter Operational Considerations: Maintenance, Cold Starting, and Freeze Protection 1. Winter Maintenance Essentials for Northern Regions To address potential low-temperature conditions in Suzhou winters, Chengli sewage treatment vehicles adopt the following maintenance strategies: - Engine Preheating System: Standard-fit intake preheater ensures smooth cold starts. - Chassis Lubrication: Use of winter-grade lubricating oil minimizes wear. - Pipeline Insulation: Sewage pipelines wrapped with thermal insulation material prevent freezing. - Battery Maintenance: Electrolyte specific gravity checked regularly to ensure adequate discharge capacity at low temperatures. 2. Cold-Weather Starting Recommendations Per Chengli’s after-sales service manual (referencing CLW5070GSSD6 official announcement parameters), the following practices are recommended for cold-weather starting: - Start the engine only after the preheat indicator light extinguishes; avoid repeated cranking attempts. - Allow the engine to idle for 3–5 minutes post-startup until coolant temperature rises above 40°C before driving. - Use No. -10 or No. -20 diesel fuel to prevent waxing. - Install a fuel heater when necessary to improve cold-start success rate. 3. Freeze-Protection Measures Freeze protection is critical for winter operations: - Antifreeze agents added to radiator and sewage tanks; concentration adjusted according to local minimum ambient temperature. - Residual liquid drained from pipelines after daily operations to prevent overnight freezing. - Seals inspected regularly to prevent leakage caused by cold-induced contraction. III. Winning Bid Analysis: Key Advantages of Chengli Sewage Treatment Vehicles The core reasons for Chengli’s successful bid in this case include: - Comprehensive Regulatory Compliance: Model CLW5070GSSD6 is listed in the MIIT Announcement, enabling nationwide registration and annual inspection, fully meeting Suzhou’s local environmental compliance requirements. - Transparent Configuration Options: Chengli offers no bundled pricing packages; purchasers may freely select chassis and upper-body configurations, eliminating hidden costs. - Robust After-Sales Support: Dongfeng chassis covered by nationwide warranty; Chengli upper-body provides lifetime service support, with spare parts shipped within 24 hours—ideal for winter emergency response. Based