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).

Completely different. The assessment of commercial vehicles focuses on: the extent of wear/deformation in the cargo area, whether the frame has been twisted due to overload, the fatigue of the leaf springs, and the emissions of the diesel engine. Minor exterior scratches carry very little weight in the assessment of commercial vehicles.

The nameplate date is the absolute time when the vehicle leaves the factory; the registration date is when the vehicle is registered with the traffic management department after sale. The difference represents the time the vehicle spent in the dealer's warehouse or logistics. If the time difference exceeds 6-8 months, the vehicle is considered a "stock vehicle," and we pay special attention to the natural aging of its rubber components.