When sourcing pistons, you must prioritize material composition and dimensional accuracy. Ensure the pistons are made from high-silicon aluminum alloys (e.g., ZL109 or AlSi12CuMgNi) for superior thermal stability and low expansion. Verify that the piston skirt coating (such as Graphite or Tin plating) meets OEM standards to reduce friction. Crucially, confirm the compression height, pin diameter, and ring groove dimensions match the specific Mitsubishi engine model (e.g., 4D56, 4G63, or 6D16) to prevent catastrophic engine failure.