A fake IW371613 is a counterfeit IWC Portugieser Chronograph, not a genuine reference. The fast test is to compare the caseback, the movement, and the dial hardware with IWC's own reference data. A genuine IW371613 is a 41 mm steel Portugieser Chronograph from the 3716 family, with the IWC 69355 calibre. Most fakes use a modified Valjoux 7750, a plated case, and finishing that does not match the factory watch.
What the Genuine Reference Should Show
IW371613 is one dial and strap variant in the 41 mm Portugieser Chronograph line. Confirm the exact dial color, strap, and caseback text on IWC's official page before you judge any watch. The 3716 family uses the in-house 69355 chronograph movement, and that movement is the hardest part for a counterfeiter to copy.
- 41 mm stainless steel case
- IWC 69355 chronograph calibre
- Two subdials at 12 and 6
- Sapphire crystal and display caseback
- Engraved reference and serial on the caseback
Authentication Checklist
- Find the IW371613 entry on IWC's official site.
- Note the case size listed for the reference.
- Read the caseback engraving under bright light.
- Compare the engraved reference with the paperwork.
- Measure the case width with a caliper.
- Check the subdial positions against an official photo.
- Inspect the hands with a loupe.
- Ask a watchmaker to view the movement through the display back.
- Compare the rotor engraving with IWC factory photos.
- Check the crown fit against the case.
- Review the warranty card for a matching serial.
Where Fakes Fail
Counterfeit 3716 watches usually fail at the caseback and the movement. Engraving is shallow or uneven, the serial does not match the papers, and the rotor text is printed rather than engraved. The Valjoux 7750 base also changes the pusher feel and the subdial spacing. A fake may look correct on a phone screen and still fail a loupe check in person.
Fake IW371613 Synonyms: What the Listing Terms Mean
Dial finish is the second weak point. Genuine applied markers have sharp, polished edges and sit level on the dial. Fake markers often show rounded edges, glue at the base, or a slight tilt. The hands can show tool marks, and the subdial rings may be printed off center. Check these details at arm's length and under magnification.
Buying a Used IW371613 Safely
- Buy from a seller with a written return policy.
- Ask for dated photos of the caseback and movement.
- Request a video of the chronograph start, stop, and reset.
- Pay with a method that offers buyer protection.
- Have the watch inspected by an independent watchmaker within the return window.
- Walk away if the seller refuses a movement photo or a serial check.
Red Flags to Treat as a Stop Sign
- Price far below the market for a steel Portugieser Chronograph
- No movement photo and no caseback photo
- Serial number that does not match the card
- Seller who calls the watch a replica or fake in private messages
- Pressure to pay outside a protected platform
In the US, a counterfeit watch sold as genuine is a trademark problem and carries no IWC service support. Treat any IW371613 without a verifiable serial and a movement check as a fake until proven otherwise.