Short answer
IW938 is not a catalogued IWC Portofino reference. IWC Portofino numbers in current and past catalogs run IW3565, IW3910, IW4586, IW5101 and IW5164, among others. A listing that shows "IW938" uses a number that does not appear in IWC records. Comparison work starts with the real reference engraved on the caseback. That number sets the case size, the caliber and the dial layout you are checking against.
Portofino references to check against
- IW3565 Portofino Automatic: 40 mm case, 9.2 mm thick, Caliber 35111, 42 hour power reserve, 28,800 vph.
- IW3910 Portofino Chronograph: 42 mm case, 13.6 mm thick, Caliber 79320, 44 hour reserve, 30 m water resistance.
- IW4586 Portofino Automatic 37: 37 mm case, Caliber 35111, date aperture at 3.
- IW5101 Portofino Hand-Wound Eight Days: 45 mm case, Caliber 59210, 192 hour reserve, power reserve display at 9.
Movement
Replica Portofino watches use Miyota 9015, Seagull ST2130 or Asian 2824 clones. Most of these run at 28,800 vph, the same rate as Caliber 35111, so beat rate alone does not separate the two. Look at rotor engraving, perlage on the bridges, blued screws and jewel count. On the IW5101, the reserve is the test. No replica holds 192 hours. Wind the watch to full reserve, set it down, then check it after 48 hours. A clone stops.
Dial and case checks
- Printing: genuine Portofino print sits under a lacquer layer. Replica print sits on the surface and reflects light at an angle.
- Date aperture: replica apertures are cut square with rough edges. Genuine apertures have a bevel.
- Crystal: IWC fits sapphire with anti reflective coating on the inner face. Replica coating shows a blue or purple tint at the edge.
- Crown: Portofino crowns carry the IWC logo. Replica crowns are blank or show a shallow stamp.
- Hands: genuine leaf hands are polished on the top face and matte on the sides, with no burrs at the tip.
Caseback and weight
Replica caseback engraving is laser cut and flat. The reference number, the "International Watch Co" script and the Schaffhausen line sit in one plane. Genuine engraving has depth and a matte finish inside the cuts.
Buy Fake Portofino Ref IW938 Watch: Specs, Prices & Pitfalls
A steel Portofino Automatic at 40 mm weighs about 65 g on a leather strap. A solid rose gold version sits near 110 g, because 18k gold has a density of 15.5 g/cm3 against 7.9 g/cm3 for steel. A gold plated replica stays close to 70 g.
Fake Portofino Ref IW938 Watch Price: What to Pay and What to Avoid
Price gap
Genuine IW3565 lists near $5,400. IW3910 lists near $6,700. IW5101 lists near $22,000 in rose gold. Replica versions sell for $200 to $500. The gap tracks the movement, the case metal and the finishing hours. If a seller quotes an eight day reserve, a solid gold case and a $300 price, two of those three claims are false.