Fake IW371648: The Short Answer
The reference IW371648 sits in IWC's Portugieser Chronograph line, and replicas of it come in three rough tiers. Budget fakes run a quartz or generic automatic movement behind a dial that looks close in photos and wrong in the hand. Mid-tier fakes use a Seagull ST19 or an ETA chrono base, which gives a passable pusher feel but the wrong finish. The best "super clone" versions copy the case profile and dial layout well, and still miss on engraving depth, subdial spacing, and movement decoration.
If you are trying to work out whether a watch in front of you is real, the reference number is your starting point, not the seller's photos.
Confirm What IW371648 Should Look Like
IWC has made many Portugieser Chronograph variants, and dial colors, hands, and strap options change between them. Before you judge anything, pull the exact reference from IWC's own product record. That gives you the correct case size, dial color, index style, and movement caliber for that number. A seller who cannot match those basics is not selling a real watch. This step takes five minutes and kills most bad deals before money changes hands.
Dial Details That Give a Fake Away
Subdial spacing and layout
The Portugieser Chronograph runs small seconds at 6 and a 30-minute counter at 12. On genuine watches those subdials sit in a specific relationship to the center and to the numerals. On fakes they drift, usually closer together or pushed outward. Hold a straight edge across the dial and compare.
Numerals, hands, and print
Applied numerals on the real thing are cut with sharp edges and sit flat. Replicas tend to have thicker numerals with rounded edges, or printed numerals that look flat under a loupe. The IWC name and the Schaffhausen line should be crisp and evenly spaced. On fakes the lettering is often a hair too bold, or the spacing is off by a fraction. Leaf hands should be polished on top and matte on the sides.
Case, Crystal, and Pushers
Check lug shape, crown size, and pusher height. Genuine pushers have a firm, short throw. Fakes often feel mushy or travel too far. The crystal on a real Portugieser has a mild dome and almost no distortion at the edges. Cheap sapphire or mineral substitutes show a visible ring or a color fringe near the rim. Run a fingernail along the case flanks. Genuine cases are finished evenly, with a clean line between brushed and polished surfaces.
Caseback, Movement, and Engraving
Engraving depth is one of the hardest things for a replica maker to match. Real engraving is cut into the metal. Fake engraving is often laser-etched and shallow, or filled with paint. If you can see the movement, look at the finishing. The column wheel, bridges, and rotor decoration on a genuine IWC are done to a standard that replicas rarely reach, even the expensive ones.
Price and Paperwork Reality
A genuine steel Portugieser Chronograph sells new in the mid four figures and up. Used examples hold a large share of that. Any offer at a small fraction of market price is a replica, full stop. Boxes, booklets, and cards are easy to fake, so treat paperwork as a bonus and not as proof. A watchmaker can open the caseback and confirm the movement for a small fee. That is the only check that settles the question.
Quick Checklist
- Match the exact reference against IWC's own record.
- Compare subdial spacing with a straight edge.
- Look at numeral edges and print crispness under magnification.
- Feel the pushers and crown for a short, firm action.
- Inspect engraving depth on the caseback.
- Check the asking price against real sold listings.
- Have a watchmaker view the movement before you pay.
If You Already Bought One
Get a written opinion from a watchmaker, then decide what to do. If you bought from a dealer who described the watch as genuine, that is a misrepresentation issue, and you may have recourse through your payment method. If you bought it knowing it was a replica, the honest move is to treat it as what it is and not pass it on as real. Reselling a fake as genuine is fraud.