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).

From a technical perspective, China's "National VI B (China VI-b)" is one of the strictest emission standards globally, with limits on carbon monoxide, nitrogen oxides, and particulate matter that are even stricter than some of Europe's Euro VI standards. However, the two are not legally recognized by each other, depending on your country's import regulations.

Complete records represent underlying trust and zero odometer adjustment risk. In the used car market, solid data history itself carries a high premium. The extra few hundred dollars buys you an impeccable endorsement when selling overseas.