The best fake IW371431 is the replica that matches the genuine Portugieser Chronograph on three points: a 41mm case, running seconds in the sub-dial at 6 o'clock, and a working chronograph with its minute counter at 12. Top-tier versions sell for about $400 to $700 and use a clone of the Valjoux 7750 architecture that IWC reworks as its caliber 79350. Cheaper copies get the dial layout wrong or hide a quartz movement behind a decorated plate.
Fake IWC IW371431: How to Spot a Replica Portuguese Chronograph
What the genuine IW371431 looks like
Reference IW371431 sits inside the IW3714 Portugieser Chronograph family, a line IWC has built in one form or another since the late 1990s. The case is stainless steel at 41mm, about 12.5mm thick, with a lug width near 20mm and 30m water resistance. Sapphire crystals front and back, a two-register dial, and no date window.
The movement
Caliber 79350 is a modified Valjoux 7750. IWC removes the 7750's small-seconds hand from 9 o'clock and drives running seconds at 6 instead, which is why the sub-dial layout looks odd next to other chronographs. Power reserve lands near 44 hours, and the rotor carries the IWC Probus Scafusia engraving.
Dial details that separate good from bad
- Applied Arabic numerals, polished with faceted edges. Cheap reps use stamped, flat markers.
- Leaf-shaped (feuille) hands with a clean center ridge. Look for a crisp line down the middle of each hand.
- Sub-dials with fine concentric finishing and hands that sit level with the dial, not floating above it.
- Dial text that lines up under a loupe. Font weight and letter spacing are the first things a watchmaker checks.
What makes one fake IW371431 better than another?
Four things decide it: case profile, dial printing, hand finish, and the movement inside. A replica can look right in a photo and fail all four in the hand.
- Case profile. The bezel slope and lug curve should follow the genuine. Thick, slab-sided cases are the classic tell.
- Dial printing. Text should be sharp and spaced right. Blurry or oversized logos mean a budget build.
- Hands and markers. Polished bevels, no tool marks on the edges, no flat stamped parts.
- Movement. A clone 7750 with a working chrono and a smooth sweep. Quartz fakes tick once per second and the pushers feel dead.
How do replica tiers compare?
- Entry ($80 to $150). Quartz or rough automatic, wrong sub-dial spacing, often over 14mm thick. Reads as a fake from a meter away.
- Mid ($200 to $350). Clone 7750, decent dial, but shallow caseback and crown engraving, and the crystal lacks anti-reflective coating.
- Top tier / 1:1 ($400 to $700). Correct 41mm case, double AR sapphire, clone 7750 with a working chronograph, deep caseback engraving. The closest you get without buying the real watch.
Prices move with seller and batch, so treat these as ranges rather than fixed numbers. The jump from mid to top tier buys dial printing and case finishing, not a different movement.
How to check a fake IW371431 before paying
- Ask for a video, not photos. Have the seller hold the watch and let the seconds hand run for 30 seconds.
- Watch the chronograph start, stop, and reset. A clone 7750 snaps back to zero. A quartz fake resets with a jerk, or not at all.
- Ask for case thickness with calipers. Anything past 13.5mm is wrong for this reference.
- Request a close-up of the dial text and the caseback engraving under direct light.
- Confirm the crystal has AR coating on both sides. A good dial looks almost invisible under the glass.
- Get the return policy in writing before you send money.
What no fake IW371431 gets right
- Movement finishing. The 79350 has Geneva stripes and a signed rotor; clones fall short on both.
- Service. No watchmaker will fit IWC parts to a clone movement.
- Water resistance. Treat 30m as splash only on a replica, whatever the caseback says.
- Resale. A replica is worth close to nothing the day it lands.
Is a fake IW371431 legal to buy?
Rules differ by country. In the US, importing counterfeit goods is illegal and Customs can seize the parcel, while selling a replica as genuine is fraud. Some EU states treat even a personal purchase as a criminal matter. Check your local law before you order, and never resell a replica listed as an IWC.
Frequently asked questions
How much should a good fake IW371431 cost?
Expect $400 to $700 for a top-tier version with a clone 7750 and a correct case. Under $200 you are buying a quartz watch in a lookalike shell.
Does the replica chronograph work?
On decent replicas, yes. The pushers start, stop, and reset the center seconds and the counter at 12. On cheap ones the pushers are decorative.
Can a watchmaker tell it is a fake?
Yes, in minutes. The movement, the depth of the caseback engraving, and the dial printing under a loupe give it away. No replica passes a service center inspection.
Will a fake IW371431 keep time?
A clone 7750 runs within about 15 to 30 seconds a day out of the box. A watchmaker can regulate it, though parts are generic and not interchangeable with the real caliber.
Is a replica worth it over a used genuine IW3714?
Only if you want the look and accept zero resale. A used genuine holds value and can be serviced for decades; a replica cannot do either.