The Short Answer
A watch sold as a fake IW371640 is a counterfeit of an IWC Portugieser Chronograph, and the money saved up front is usually paid back through customs seizure, no warranty, no parts availability, and a resale value near zero. If the goal is the Portugieser look on a smaller budget, buy a genuine pre-owned IWC or a plainly branded homage that carries its own name. If the goal is simply to tell a real IW371640 from a counterfeit, the checks below are the ones that matter.
What the Reference Number Tells You
IWC reference numbers are not decorative. Each one maps to a specific combination of case material, dial, hands, strap, and often movement. Before spending money on anything labeled IW371640, confirm the exact configuration on the manufacturer's own reference page and compare it line by line. A seller who cannot state the case size, movement family, water resistance rating, and original strap option in the same breath is usually describing a photograph rather than a watch.
What to Look For in a Genuine Portugieser Chronograph
Case and proportions
- Diameter in the 41 mm range for the modern chronograph, with a thickness of roughly 13 mm to 14 mm.
- Lug width around 20 mm, with lugs that curve toward the wrist instead of sitting flat.
- Polished and brushed surfaces meeting on a crisp, straight line. Rounded or washed-out edges are a warning sign.
Dial and counters
- Two chronograph counters, arranged according to the variant, with printed scales that stay sharp under magnification.
- Applied numerals or indices with clean edges and even lume fill, where the variant uses lume.
- Text and logo sitting level. Crooked printing is the most common tell on a counterfeit.
Movement
The chronograph should start smoothly, reset to zero instantly, and the pushers should feel crisp rather than spongy. A counterfeit typically hides a quartz or low grade automatic movement under a decorated rotor. Ask for a clear movement photograph with the caseback removed and expect finishing to be consistent on every visible surface.
Pitfalls
- Customs seizure. Counterfeit watches are illegal to import into the United States, and shipments can be detained and destroyed.
- No service path. No authorized watchmaker will touch a counterfeit, and replacement parts do not exist.
- Manufactured reviews. Replica storefronts recycle the same photographs and testimonials across dozens of domains.
- Payment risk. Wire transfers and cryptocurrency remove any chargeback option.
- Resale. A counterfeit has no honest market and cannot be sold on.
Legal Alternatives
Genuine pre-owned Portugieser Chronographs trade regularly, and a full set with box and papers holds value. If the budget will not stretch that far, brands that build their own chronographs in a similar visual language give you a real warranty and a real service network. Homage watches are legal when they carry the homage maker's own name and do not copy protected logos or trade dress.
FAQ
Is a fake IW371640 worth buying?
No. The purchase price is the smallest cost. Seizure, repairs, and resale loss usually exceed it.
How do I verify the reference number?
Use the manufacturer's own product page and an authorized dealer. Cross check case size, dial layout, and movement description against the listing.
Can a counterfeit pass as genuine?
At arm's length, sometimes. Under a loupe or on a timing machine, almost never.
What should I ask a private seller?
Ask for the original purchase date, service history, box and papers, and high resolution photographs of the caseback, crown, and clasp.