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).

4S dealership records are directly connected to the manufacturer's database, making the data hard to tamper with and the most reliable, with original parts guaranteed; third-party repair shops usually are not connected, making their data unverifiable. Therefore, we only consider the connected records from 4S dealerships as valid historical documentation.

If your market is in extremely cold regions (like Russia or Northern Europe), we strongly recommend purchasing ternary lithium (NMC) models equipped with heat pump air conditioning. The range achievement rate of used LFP batteries typically plummets at minus 15 degrees, and we will alert you accordingly.