Sewage treatment vehicle procurement in the high-altitude environment of Lhasa: A deep analysis from cost to maintenance. In cities like Lhasa—characterized by high elevation—procurement of municipal sanitation equipment involves not only initial investment but also long-term operational reliability. Particularly for sewage treatment vehicles, core functionality relies heavily on hydraulic systems and freeze resistance; however, the low-oxygen, low-temperature plateau environment poses exceptional challenges to these systems. This article takes a real-world case—where a municipal sanitation department procured National VI Dongfeng sewage treatment vehicles with a 3308 mm wheelbase—as its entry point, offering procurement decision-makers an actionable reference guide across dimensions including total cost of ownership (TCO), major overhaul intervals, depreciation characteristics, and winter maintenance strategies. Case Background: Practical Requirements in High-Altitude Regions In 2025, the Urban Management Bureau of a district in Lhasa planned to procure a batch of National VI emission-standard sewage treatment vehicles with a 3308 mm wheelbase to meet local sewage treatment demands. The selected model needed to operate reliably at altitudes above 3,500 meters, start normally at temperatures as low as −20°C, maintain stable hydraulic system performance, and effectively handle wastewater containing solid particles. Following a public tender process, Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as “Chengli”) submitted a competitive solution priced at approximately RMB 420,000 per unit (based on publicly available tender information), delivering three units. Feedback from current operations has been positive. Total Cost of Ownership (TCO): Comparison Across 5-, 8-, and 10-Year Periods The cost of a sewage treatment vehicle extends beyond its purchase price to include fuel, routine maintenance, major overhauls, and residual value. Below is an estimated TCO analysis for 5-, 8-, and 10-year periods, based on Chengli’s vehicle configuration (chassis referencing Dongfeng’s 3308 mm wheelbase, with Chengli-customized upper structure) and operational data from the Lhasa region. Cost Item 5-Year Period 8-Year Period 10-Year Period Purchase Cost (including tax and delivery) ~RMB 420,000 ~RMB 420,000 ~RMB 420,000 Annual Fuel Cost (200 operating days/year; ~15% higher fuel consumption due to high-altitude conditions) ~RMB 32,000/year (RMB 160,000 total) ~RMB 32,000/year (RMB 256,000 total) ~RMB 32,000/year (RMB 320,000 total) Annual Maintenance & Service Cost (including hydraulic oil, antifreeze, filters, etc.) ~RMB 15,000/year (RMB 75,000 total) ~RMB 18,000/year (increased wear from Year 6 onward; RMB 144,000 total) ~RMB 20,000/year (major overhaul cycle begins Year 8; RMB 200,000 total) Major Overhaul Costs (hydraulic system, engine, sewage pump) None (no major overhaul required within 5 years) ~RMB 50,000 (Years 6–7) ~RMB 120,000 (hydraulic pump & sewage pump replacement in Year 8; engine mid-overhaul in Year 10) Residual Value (estimated based on Chengli vehicle depreciation patterns) ~RMB 150,000 (depreciation rate ~64%) ~RMB 80,000 (depreciation rate ~81%) ~RMB 30,000 (depreciation rate ~93%) Total Cost of Ownership (TCO) ~RMB 505,000 ~RMB 790,000 ~RMB 1,030,000 Note: All figures are estimates derived from Chengli’s official vehicle specifications, local Lhasa operational cost data, and publicly disclosed tender information. Actual costs may vary depending on usage frequency and maintenance standards. Major Overhaul Cycle: Under High-Altitude Conditions