All our measuring instruments (especially calipers, paint thickness gauges, and refrigerant pressure gauges) are calibrated quarterly according to ISO quality management system requirements to ensure the data we provide you is objective, accurate, and reliable.

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.

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).