Short answer
A fake IW371654 is a counterfeit copy of an IWC Portugieser Chronograph. Genuine watches in the 3716 reference block use a 41 mm steel case, two chronograph registers on a vertical axis, and in-house calibre 69355. Copies sell for $150 to $600. Genuine steel models trade at $4,000 to $7,000 on the used market. A copy matches the outline. It does not match the movement, the engraving, or the production record.
I found no public IWC listing for the exact dial and strap combination of IW371654. References in the 3716 block cover several dial colors and case metals. Confirm the number with an IWC boutique or the IWC reference page before you buy.
Genuine IW3716 data points
- Case: 41 mm across, stainless steel, 20 mm lugs.
- Dial: chronograph minutes at 12, small seconds at 6. Crown at 3, two pushers.
- Movement: calibre 69355, automatic, column wheel, 28,800 vph, power reserve near 46 hours.
- Caseback: sapphire display back. The rotor carries Geneva stripes and an IWC mark.
- Older 3714 versions used a Valjoux 7750 base. Current 41 mm versions use calibre 69355.
Where copies fail
Movement
Most fakes run a Chinese 7750 copy or a Seagull ST19. The pusher action feels soft. The rotor spins with a rattle. A genuine 69355 starts the chronograph with a light click from a column wheel. Ask for a movement photo or a rate reading from a watch timing machine.
Dial
Check register spacing, numeral shape, and print weight. Copies set the subdials off the vertical axis. Print on fakes shows ragged edges under 10x magnification. Feuille hands on the genuine watch have polished bevels and a matte center.
Case and caseback
Engraving depth differs. Genuine reference numbers and case numbers are cut into the metal, not laser-etched. Font weight and spacing match IWC records. A copy shows shallow marks. IWC engraves a case number and a serial number on separate lines. Ask IWC to confirm both against their records.
Papers and boxes
Fake kits ship with printed booklets and unbranded boxes. Genuine IWC boxes have a set finish and a numbered card. A receipt from an authorized dealer or a service record from IWC carries weight.
Checks before you buy
- Ask for a caseback photo and compare the reference number.
- Request a movement photo or a timing machine reading.
- Compare dial photos against an IWC image of the same reference.
- Check the case number and serial number with an IWC boutique.
- Compare the asking price against current listings on Chrono24 or a dealer site.
- Pay with a method that allows a chargeback. Avoid bank transfer.
Price signals
Genuine IWC Portugieser Chronograph steel models list near $7,900 and sell used between $4,000 and $6,800. Year, dial color, and box set move that figure. A steel 3716 listed under $1,500 is a copy in most cases.
Legal note
In the United States, 18 U.S.C. 2320 sets prison terms for trafficking in counterfeit goods. Customs can seize shipments. Sale and import of counterfeit watches is illegal in the US and the EU. Personal-use rules differ by country. Resale does not.