A fake IW371628 usually shows itself at the dial first. The subdial spacing drifts, the applied numerals sit too high off the surface, and the printing looks flat and slightly fuzzy under a loupe. On a real IWC Portugieser Chronograph of this reference you get a 40.9 mm steel case, subdials at 12 and 6, and printing that sits crisp and level with the lacquer. Check the dial, then the caseback engraving, then the movement, in that order.
What is the IW371628?
The IW371628 belongs to the IWC Portugieser Chronograph family, a 40.9 mm steel watch with a chronograph counter at 12 and running seconds at 6. Earlier production used the 79350 calibre, a heavily reworked Valjoux 7750. Later production moved to the in-house 69355 with a column wheel. Because the reference spans multiple production years, confirm the exact dial variant and movement pairing before you judge a single detail.
- Case: steel, roughly 40.9 mm wide and about 12.3 mm thick
- Dial: silver-plated or coloured, applied Arabic numerals, leaf-style hands
- Layout: 30-minute counter at 12, small seconds at 6
- Crystal: domed sapphire, with a display back on most versions
How do you spot a fake IW371628 dial?
Counterfeit dials fail on depth and consistency. Genuine printing is dense and even, with no halo around the text, and the subdial rings are cut cleanly into the surface rather than stamped on top.
- Look at the text weight. Fake "IWC Schaffhausen" lettering is often thicker or unevenly spaced.
- Check numeral alignment. Applied markers on fakes sit rotated or raised, casting a lopsided shadow.
- Inspect the subdial hands. Real hands are thin, flat-polished, and reach the exact index marks.
- Compare hand colour. Gold-plated hands on fakes often read brassy or too yellow.
How do you check the case and caseback?
The caseback engraving on a genuine watch is laser-sharp, with the reference number, serial number, and hallmarks cut deep and square. Fakes use shallow etching that feels rough to a fingernail. Case flanks on a real watch are brushed evenly in one direction with polished bevels that catch light in a straight line.
Push the strap aside and look at the lugs. Counterfeit lugs are frequently too thick or too rounded, and the spring bar holes sit off centre. On a genuine watch, the caseback threads engage smoothly and the sapphire sits flush.
What should the movement look like?
Through the display back you should see proper finishing: Geneva stripes, blued screws, and a signed rotor with crisp engraving. Fakes usually show a stock movement with printed stripes, chromed screws, and a rotor text that is stamped rather than engraved. If the movement looks bright and plasticky, walk away.
How much does a real one cost?
Secondary market prices for a steel Portugieser Chronograph typically fall in the low-to-mid five figures in US dollars, depending on age, box and papers, and dial variant. A listing far below that range is the single strongest warning sign. Ask for a movement photo, a caseback macro shot, and the original warranty card before paying.
Is a fake IW371628 worth buying?
No. Counterfeit movements are unreliable, parts are not serviceable by IWC, and resale value is effectively zero. Buy a genuine pre-owned example or a well-regarded alternative instead.
Does the IW371628 have a date window?
The standard Portugieser Chronograph dial has no date aperture. If a listing shows one, verify the exact reference against IWC's own specification before you consider it.