Short answer
The replica IW371648 worth buying is the one that copies the 41 mm Portugieser Chronograph case and dial layout correctly first, and worries about the movement second. Get the size, the subdial positions, the crystal shape and the strap width right, and the watch reads correctly on the wrist from arm's length, which is where 95 percent of the judgment happens. Get those wrong and no movement upgrade will save it.
That said, the IW371648 is one of the harder Portugieser references to fake well, because the dial is nearly empty. A clean dial forgives nothing.
What the genuine IW371648 is
IW371648 belongs to the 3716 family, the 41 mm Portugieser Chronograph line IWC moved to an in-house calibre. Reference numbers inside this family cover different dial colours and strap or bracelet combinations, so the first thing I do is confirm the exact dial and strap pairing for the specific reference I am looking at, since sellers mix variants freely.
The specs a replica has to match
- Case diameter 41 mm, thickness about 13.1 mm
- Lug width 20 mm, which is narrow for the case size and easy to spot when wrong
- Chronograph with a 30 minute counter at 12 and running seconds at 6
- Railroad style minute track, applied numerals, leaf hands
- Box domed sapphire with anti reflective coating on both faces
- Rated to 3 bar, so a screw down crown is cosmetic rather than functional
- In-house calibre 69355 with a column wheel and roughly 46 hours of reserve
Where replicas get it wrong
Subdial spacing
This is the big one. On a 7750 derived movement the two subdials sit too far apart or too far toward the centre, and the 12 o'clock counter ends up crowded against the numerals. On a genuine 69355 the spacing is tighter and the dial breathes. Compare photos side by side at the same angle and the gap between the subdial edge and the minute track tells you which movement is inside.
Case profile and crown
The Portugieser case is a thin stepped cylinder with a narrow bezel. Cheap replicas make it too thick, and the step between bezel and mid case disappears. Look at the crown and pushers in profile: they should be slim, polished and slightly recessed into the case band.
Dial printing and numerals
Applied numerals should sit flat and catch light along one edge. Printed replica numerals look flat grey and the corners blur under a loupe. The minute track printing should be crisp enough to read at the 12 and 6 positions without the lines merging.
Movement
The honest tier uses a decorated Asian 7750 with the rotor engraved to mimic IWC finishing. A better tier uses a clone of the 69355 layout, which fixes the subdial spacing and lets the watch run at the correct beat. Ask for a photo of the movement through the sapphire caseback before paying. If the seller will not send one, walk.
What to check before you buy
- Ask for a wrist shot and a flat dial shot on a neutral background, not the vendor's stock renders.
- Confirm the strap is 20 mm and that the buckle matches the reference, deployant or pin.
- Check the caseback engraving. Reference numbers and serial fonts are usually where replicas slip.
- Ask about the seconds hand at 6. If it stutters visibly, the movement is a 7750 with a transfer gear and it will wear out.
- Get the return policy in writing before payment.
Price tiers and what is realistic
Expect three rough bands. Entry replicas around a hundred to two hundred dollars get the silhouette but not the dial. Mid tier copies fix the dial and strap but usually keep the 7750. The top tier, generally several hundred dollars, gets the case proportions, crystal and movement layout close enough that only a side by side comparison catches it. Nothing at any price will match the finishing on the bridges or the feel of the column wheel pushers.
Red flags
- Stock photos only, no real images of the actual unit
- Claims of genuine IWC parts or genuine movements
- No movement photo on a chronograph
- Pressure to pay outside a trackable method
One thing worth saying out loud
A replica is not an IWC, it carries no warranty from the brand, and buying or importing one carries legal and customs risk depending on where you live. Treat it as a costume piece, budget accordingly, and do not let anyone sell it to you as anything else.