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).

For B2B large customer orders, a "sampling + full inspection" dual regulation is adopted. Core parameters (no major accidents, no water damage or fire) are subject to 100% inspection per vehicle; appearance and condition are uniformly graded (e.g., uniformly purchasing Grade A), and panoramic images of all vehicles in the batch along with a core indicators comparison list are provided before shipment.

Our technical report will read the environmental information from the vehicle's factory-issued documentation (including certifications like National V, National VI, etc.). You need to submit the specific emission limit data we provide (such as grams of CO, THC, NOx emissions) to your country's environmental or customs authorities for compliance comparison.