Beijing Dongfeng double-cab sewage suction truck (blue license plate, 3 m³) government procurement case: Interpretation of the winning solution for low-temperature environments. Project background: Municipal sewage cleaning equipment procurement requirement in a district of Beijing. In early 2026, a municipal sanitation department in Beijing planned to procure a batch of specialized vehicles for sewer network, river channel, and residential septic tank cleaning operations. Considering Beijing’s winter temperatures can drop to -10°C to -20°C, and operational areas often include narrow alleys and residential neighborhoods, the procuring entity specified clear requirements: blue license plate (C-class driver’s license eligible), compact overall dimensions (to navigate height- and width-restricted roads), effective capacity of 3 m³, double-cab configuration (to accommodate work crews), and—critically—robust low-temperature adaptability. According to publicly released tender information, the project budget was capped at approximately RMB 322,000 per unit, with an intended procurement volume of 3–5 units. Following multiple rounds of technical evaluation and commercial negotiations, Chengli Special Purpose Vehicle Co., Ltd. successfully delivered the Dongfeng double-cab sewage suction truck (blue license plate, 3 m³; model CLW5040TQYD6). Current user feedback is highly positive. Analysis of major competing brands and products: This procurement attracted bids from several leading special-purpose vehicle manufacturers, including Chengli, Foton, Sinotruk (Howo), and FAW Jiefang. All submitted 3 m³ sewage suction trucks compliant with blue license plate standards (gross vehicle weight ≤ 4,500 kg); however, significant differences existed in detail configurations and low-temperature performance. 1. Foton Ouman Sewage Suction Truck: Foton enjoys high market penetration in Beijing and maintains an extensive service network. Its offered 3 m³ model features a Cummins 2.8L engine delivering strong power output—but uses a single-cab configuration, failing to meet the double-cab requirement. Moreover, its hydraulic system lacks specific optimization for extreme cold; hydraulic oil warms up slowly after cold starts, reducing operational efficiency. 2. Sinotruk Howo Sewage Suction Truck: While Sinotruk Howo chassis are well-regarded in heavy-duty truck segments, its light-duty truck experience in the sewage suction niche remains limited. Its double-cab variant features a longer wheelbase and larger turning radius, compromising maneuverability in old residential communities and narrow streets. Additionally, it employs standard hydraulic oil, whose viscosity increases significantly below -15°C, risking hydraulic pump cavitation. 3. FAW Jiefang Tiger-V Sewage Suction Truck: The Tiger-V chassis offers a double-cab layout, yet no dedicated blue-license-plate 3 m³ sewage suction truck model appears in official type-approval announcements. Custom modification would be required, entailing extended lead times (≥60 days), rendering it unsuitable for urgent procurement needs. Furthermore, compatibility between its chassis and upper-body equipment remains unverified. 4. Chengli Dongfeng Double-Cab Sewage Suction Truck (Model CLW5040TQYD6): Chengli’s offering is built upon the Dongfeng Duolika D6 double-cab chassis (model CLW5040TQYD6, referenced in MIIT type-approval documentation), powered by a Quanchai Q23-95E60 engine (95 hp), compliant with China VI emission standards. Its three core advantages are: (i) Standard-fit intake air preheater + fuel heater enabling one-button engine start at -25°C; (ii) Use of low-temperature hydraulic oil (rated for -35°C), ensuring rapid hydraulic response and preventing cylinder sticking under freezing conditions; (iii) Internal tank coating with corrosion-resistant and thermal-insulation layers, preventing residual wastewater from freezing and damaging the pump after winter operations. Key parameter comparison: Low-tempera