We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).

Odometer fraud exists everywhere, but cross-checking several data points makes it hard to fake: 1) Maintenance records: ask for service history with mileage entries. Gaps or resets are red flags. 2) Tire wear: a car showing 30,000 km should not have nearly bald tires. Compare tread depth against the claimed mileage. 3) Pedals, steering wheel, and seat bolsters: heavy wear on these with low odometer readings is a classic mismatch. 4) Diagnostic scan: request an OBD readout. Many control modules store mileage data internally — if the ECU shows 120,000 km while the dash shows 40,000, you have your answer. 5) Vehicle history report: in China, apps and platforms can pull insurance claim records and registration history, which often reveal the true mileage trail. Always request a live video showing the odometer with the engine running, and have the number written into your contract.

Currently, in most developing countries, there is a severe lack of deep repair capabilities for the three electric systems. We recommend that B2B car dealers must have basic electrical insulation testing capabilities.