The short answer
A counterfeit IW371790 is not a shortcut to a luxury watch. It is an illegal copy, it will not hold value, no authorized service center will repair it, and it carries legal risk for anyone who imports or resells it. If you want the look of an IWC Portugieser Chronograph, the workable paths are a genuine pre-owned example, an authorized dealer purchase, or a well-made watch from a brand at a lower price point. The sections below explain how to verify the reference you are looking at, which details separate a real Portugieser from a copy, and how to buy a genuine watch without overpaying.
Confirm the reference before you shop
IWC reference numbers are exact. Numbers in the IW3717 range sit inside the Portugieser Chronograph line, and a change of one digit can mean a different case size, dial layout, movement, or production era. Before you compare two watches, look up the exact reference in the manufacturer's own product archive or ask an authorized dealer to confirm it. A seller who cannot state the reference, the case diameter, and the movement calibre in a single sentence is usually working from a stock photo.
What separates a genuine Portugieser Chronograph from a copy
Case and finishing
- Genuine cases show crisp, even transitions between brushed and polished surfaces. Copies show rounded edges and blurred lines.
- Case backs carry deep, sharp engraving with correct reference and serial formatting. Laser etching looks shallow and slightly grey.
- Lugs meet the strap with no gaps. Aftermarket fakes often leave a visible step.
Dial and hands
- Applied numerals sit flat and reflect light in one direction. Printed substitutes sit slightly proud and look dull.
- Subdial spacing matches the movement underneath. A chronograph built on a stock third-party layout often places the subdials and date window differently from the real watch.
- Hands are polished on every side, including the underside. Cheap copies leave tool marks.
Movement
The 41 mm Portugieser Chronograph runs an in-house automatic chronograph calibre with a power reserve of roughly two days and a beat rate of 28,800 vibrations per hour. Pushers should start, stop, and reset with a firm, even click. A soft or gritty feel points to a stock chronograph module.
Papers, box, and history
Genuine watches arrive with a warranty card, a serial number, and paperwork that ties the two together. Ask for a service history. A seller who refuses an independent inspection has already answered your question.
Pitfalls that cost buyers the most
- Super clone claims. The phrase says nothing about quality and everything about the seller's marketing budget.
- Photos of a real watch, delivery of a fake. Insist on dated photos of the actual piece with the serial visible.
- No return window. Any legitimate seller offers a return period long enough for an inspection.
- Untraceable payment. Wire transfers and gift cards remove your only leverage.
- Factory service expectations. No maker will service a counterfeit, so the cheaper long run argument fails on day one.
Buying the real thing without overpaying
Pre-owned Portugieser Chronographs trade below retail, and full sets with box and papers hold value better than loose watches. Buy from a dealer who provides a written authenticity guarantee, budget for a service if the watch is more than five years old, and factor that cost into your offer. If the genuine watch is out of reach today, a mid-range chronograph from a reputable brand will serve you better than a counterfeit that cannot be repaired, resold, or worn with confidence.
FAQ
Is a fake IW371790 worth buying?
No. It is illegal to import or resell in the United States, it has no resale value, and no authorized service center will touch it.
How do I check a reference number quickly?
Use the manufacturer's own product archive or ask an authorized dealer. Collector-built reference databases help with cross-checking, but they should not be your only source.
What should a genuine watch include?
The watch, a warranty card or service record, the original box, and a serial number that matches across every document.
Can a counterfeit pass as genuine in photos?
Often, yes. That is why an in-person inspection or an independent watchmaker's report matters more than any listing image.