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).

We cannot open each tire to inspect the inside. However, if a visual inspection reveals severe creases on the tire sidewall, it indicates that the run-flat tire has been driven for a long time at zero pressure, damaging its internal structure. We would recommend replacing it before shipping.

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.