A fake IW371497 usually gives itself away in three places: the subdial spacing and dial printing, the chronograph movement visible through the sapphire case back, and the depth and crispness of the engraving on the case back. Genuine IWC Portugieser Chronograph ref. IW371497 watches run the in-house calibre 69355, an automatic column-wheel chronograph, while most replicas substitute a modified Valjoux 7750 or a generic Asian chronograph movement that looks nothing like it under magnification.
What is the IW371497?
The IW371497 is a Portugieser Chronograph in stainless steel with a silver-plated dial, gold-plated hands and indices, and a 41 mm case. It belongs to the ref. 3716 family that IWC introduced in 2020 as the successor to the long-running ref. 3714 line.
- Case: 41 mm stainless steel, about 13 mm thick
- Movement: IWC calibre 69355, automatic chronograph with column wheel, roughly 46 hours of power reserve
- Dial: silver-plated with two vertically stacked subdials at 12 and 6, feuille (leaf) hands
- Crystal: domed sapphire with anti-reflective coating on both sides
- Water resistance: 30 m (3 bar)
- Strap: leather with a signed steel pin buckle
What gives a fake IW371497 away fastest?
Dial layout is the quickest check. On the genuine watch the two subdials sit on a clean vertical axis with even space above and below the center, and the signature under the 12 is sharp and evenly spaced.
Replica dials often show thick or smeared printing, misaligned numerals, and subdials spaced too far apart or too close together. Look at the applied indices: genuine markers are polished gold with beveled edges that sit flat against the dial, while fakes tend to use plated brass with rounded or uneven edges.
How do you verify the movement?
Ref. IW371497 has a sapphire case back, so the calibre 69355 is visible. Genuine finishing includes Geneva stripes on the bridges, blued screws, a signed oscillating weight, and a clearly defined column wheel with a vertical clutch.
Most replicas hide a stock 7750 or a generic chronograph clone, or they simply print a fake rotor signature over undecorated plates. A rotor stamped with the IWC Probus Scafusia motto sitting above rough, unpolished bridges is a strong sign of a counterfeit.
Does the serial number prove authenticity?
No single engraving proves authenticity, but the case back carries most of the evidence. Genuine case backs show a reference number, a serial number, and crisp stamped or laser-engraved text with consistent depth across every character.
On fakes the engraving is shallow, filled with paint, or placed slightly off center. IWC can confirm a serial number through its own service channels, and the manufacturer or an authorized dealer is the only source that can give a definitive answer.
What about case finishing and hardware?
Genuine cases are machined from stainless steel and finished with alternating satin brushing and mirror polishing. The transitions between brushed and polished surfaces are straight and sharp, and the chronograph pushers have a firm, defined click.
Replicas often show wavy brushing, rounded lug edges, and pushers that feel mushy or grind. Weight is another clue: a genuine steel Portugieser Chronograph feels substantial for its size, while many fakes feel light or oddly heavy because of plated base metal.
Do the strap, buckle, and box matter?
Genuine IW371497 watches ship on leather with a signed steel pin buckle, and the buckle engraving is deep and centered. Many replicas use coated leather and buckles with shallow, off-center stamps.
Boxes and papers are copied on a large scale, so packaging alone should never be treated as proof. A complete set with a matching serial number adds value, but it does not guarantee a genuine watch.
Quick authenticity checklist
- Check subdial spacing and dial print under a loupe.
- Confirm the movement through the sapphire case back.
- Inspect engraving depth and serial formatting on the case back.
- Compare pusher feel and crown action.
- Check brushing quality and case weight against reference photos.
- Verify the serial with IWC or an authorized dealer before buying.
Is a cheap IW371497 always fake?
In practice, yes. A genuine IWC Portugieser Chronograph typically sells for roughly USD 6,500 to 8,500 depending on age and condition, so listings far below that range are almost always counterfeit or misrepresented.
Buying or selling counterfeit watches is illegal in the United States, and shipments can be seized by US Customs and Border Protection. When comparing a genuine reference to a replica, the reliable tests are the movement and the case back engraving, not the box or the seller's story.