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).

Always rely on the original factory network data from the 4S store. Third-party platforms may have delays or errors when capturing data (such as incorrect VIN entry). In case of a conflict, we rely on physical verification of the actual vehicle to resolve the data discrepancies.

Many car owners do not have their first maintenance done at authorized dealerships, leading to gaps in early data. In such cases, we do not blindly trust the odometer; instead, we analyze the tire production dates and wear levels, as well as the depth of grooves on the brake disc edges, using the "gold standard" of physical wear to infer the intensity of early use.