Government procurement case of CN6 Dongfeng 3308 mm wheelbase sewage treatment vehicle in Taiyuan: Solution interpretation and bid-winning analysis. This article is based on publicly available tender information and industry cases, for procurement reference only. Specific parameters are subject to official announcements. I. Project Background and Procurement Requirements: In late 2024, a municipal sanitation department in Taiyuan City issued a procurement tender for CN6-emission-standard sewage treatment vehicles to address urban sewer network cleaning and emergency response needs. According to publicly disclosed tender information, the project budget was capped at approximately RMB 959,000, with plans to procure two units at an estimated unit price of around RMB 420,000. The procuring entity explicitly required the vehicle chassis to be from the Dongfeng series, with a wheelbase of 3308 mm and CN6 emission compliance, and specifically emphasized stable operational capability under Taiyuan’s winter low-temperature conditions (–15°C to –20°C)—including cold-start performance, low-temperature hydraulic system stability, and a comprehensive winter maintenance plan. Located in North China, Taiyuan experiences cold, dry winters; conventional sewage treatment vehicles often encounter difficulties such as hard starting, hydraulic oil solidification, and pipeline freezing below 0°C. Therefore, the core technical specifications for this procurement focused on: a low-temperature engine start-assist system, low-temperature-resistant hydraulic oil and insulated piping design, and a holistic vehicle winter maintenance program. Following multiple rounds of evaluation, the proposal submitted by Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as 'Chengli') was awarded the contract, and the vehicles have now been delivered and are in active service. II. Analysis of Chengli’s Bid-Winning Factors: According to publicly released evaluation results, Chengli’s proposal received recognition from the evaluation panel across the following dimensions: High Technical Solution Alignment: Chengli utilized a Dongfeng 3308 mm wheelbase chassis equipped with a CN6-compliant engine and customized a freeze-prevention start package for Taiyuan’s climate—including battery thermal insulation covers, fuel pre-heating devices, and low-temperature cold-start fluid assistance systems—to ensure reliable engine starts down to –20°C. Low-Temperature Hydraulic System Stability: Low-temperature hydraulic oil (with a pour point of –35°C) was selected; all hydraulic lines were fully insulated, and electric heating jackets were installed on critical valve assemblies to prevent hydraulic oil solidification and actuation failure in sub-zero conditions. Comprehensive Winter Maintenance Program: Chengli provided an onboard winter maintenance manual covering weekly hydraulic oil level checks, monthly antifreeze freeze-point testing, and quarterly cold-start system verification. Additionally, Chengli committed to lifelong upfit support (per Chengli’s official after-sales policy: nationwide chassis warranty, lifelong upfit service, and spare parts dispatched within 24 hours). Outstanding Cost-Effectiveness: As a direct manufacturer (per knowledge base: same-specification vehicles cost RMB 8,000–15,000 less than those purchased through 4S dealerships), Chengli’s final quoted price was approximately RMB 465,000 per unit—below the budget ceiling—and included complete documentation enabling nationwide registration. Proven Track Record on Similar Projects: Chengli maintains a case database serving over 500 municipal sanitation agencies, including delivery of ten 5-cubic-meter water-sprinkling trucks to a Henan sanitation bureau and four cleaning/suction-sewer trucks to a Sichuan municipal authority—demonstrating proven field performance in northern cold-climate regions. III. Key Vehicle Technical Highlights (Based on Reference Models Such as CLW5070GSSD6): The vehicle