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 will use a megohmmeter (insulation resistance tester) to measure the insulation resistance of the high-voltage bus. If the resistance value is below the national safety standard, it indicates a risk of leakage, and the vehicle will be deemed unqualified.

Our bulk discounts are not simply calculated by the number of units, but by shipping batches. Typically, consolidating enough for a 40-foot container (which can hold 2-3 vehicles, depending on size) can waive some logistics fees; purchasing more than 5 units at once triggers tiered discounts.