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).

If the delays are due to policy-related force majeure like customs system upgrades, or if our documentation errors lead to short shipments, all additional demurrage and storage fees incurred at ports within China will be borne by sellwellauto, and the buyer will not have to pay a cent.

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.