How should I handle “oem vs aftermarket part number cross reference” when shopping for “part number cross reference”?

Choose by failure consequence, evidence, warranty, and labor cost. OEM can simplify specification matching; a documented aftermarket part can be suitable when its application data and quality controls are clear. FTC guidance says aftermarket use alone does not automatically void a vehicle warranty, although damage caused by a defective part or installation may be excluded. Call out the most common mistake for this long-tail, then the fix. UK FAQ.