A fake IW371752 fails authentication fastest in three places: the subdial spacing at 12 and 6, the depth and font of the caseback engraving, and the finish of the movement under the sapphire back. Genuine IWC Portugieser chronographs use an in-house automatic chronograph caliber, a 41 mm case with crisp polished-to-brushed transitions, and deeply struck caseback lettering. Most fakes run a 7750-based movement with a wobbling rotor, a soft date click, and shallow laser-etched markings that sit flat under light.

What Is the IWC IW371752?

The IW371752 belongs to IWC's Portugieser chronograph reference family, a slim 41 mm two-register design with subdials stacked at 12 and 6 and a thin stepped bezel. It uses the same overall architecture as the rest of the 3717-line: applied numerals, feuille hands, and a sapphire crystal with dual anti-reflective coating. Because the design is so clean, small errors in proportion or print quality stand out badly on a fake.

Which Details Give a Fake IW371752 Away Fastest?

• Subdial spacing. The 12 and 6 registers should sit tight to the center pinion with even margins top and bottom. Fakes push them outward or inward by a millimeter or more.
• Printed text. Genuine dial printing is razor edged and dense. Fake printing looks fuzzy under a loupe and often uses a slightly different letter weight.
• Caseback engraving. Reference numbers, serial numbers, and the IWC wordmark are struck deep into the metal. Fakes are laser etched, so the letters look grey and shallow instead of reflective.
• Movement finish. A genuine caliber has Geneva stripes, a signed skeleton rotor, and blued or polished screws. Fake movements show stamped, dull plates.
• Pusher feel. Genuine chronograph pushers have a firm, short travel with a clean reset snap. Fakes feel spongy or gritty.
• Crystal coating. Genuine sapphire has a faint blue or purple AR tint at an angle. Cheap fakes are uncoated and reflect heavily.
• Weight and balance. A real IW371752 sits heavy on the wrist for its size. Many fakes feel hollow because the case is thinner and the rotor is lighter.

How Does the Movement in a Fake Compare?

A genuine IW371752 uses an in-house automatic chronograph caliber with roughly a 46-hour power reserve and a 4 Hz beat rate. Most replicas copy the look of the rotor and bridges but keep a generic 7750 architecture underneath, which changes the crown position, the date change speed, and the sound of the winding.

Listen while you wind it. A healthy genuine caliber winds smoothly with a fine, even click. A fake usually sounds dry and rattles when the rotor swings.

Dial, Hands, and Crystal Checks

Under a loupe, check the date window bevel and the alignment of the date disc in the aperture. Fakes often show a slightly off-center number or a flat, unpolished window edge. Hands on a genuine watch are polished to a mirror finish on top and matte on the sides, while fake hands are usually uniform and slightly thick.

Caseback, Serials, and Paperwork

Genuine IWC serials are 7 to 8 digits and are recorded by the brand, so a quick email to IWC's service department can confirm a watch. Paperwork should match the serial embossed on the caseback, and the warranty card should carry the same number. A seller who avoids a serial check or shows only low-resolution photos is a red flag.

Is a Fake IW371752 Worth Buying?

A watch sold as genuine but built as a fake is fraud, and it cannot be serviced by IWC. A knowingly bought high-tier replica is a different category, but even the best ones lose on movement finishing, rotor noise, and case weight. If the price is far under market for an IW371752, assume the watch is a fake until proven otherwise.

FAQ

How much does a fake IW371752 sell for?

Entry replicas run well under $300, while higher-tier versions with cloned movements climb into the low four figures. Genuine examples sell far above that range on the secondary market.

Can a jeweler tell a fake IW371752 from a real one?

Yes, usually within a minute. Caseback engraving depth, movement finish, and pusher feel are the three checks most watchmakers use first.

Do fake IW371752 watches keep accurate time?

Often they do at first. The problem is longevity, since 7750 clones wear faster and are rarely regulated to IWC tolerances.