Quick answer
One IWC Portugieser uses a 45mm case: the Portugieser Grande Complication, reference 3774. Replica factories copy that case. A replica listed at 45mm is a copy of the Grande Complication, not the 42.3mm Portugieser Automatic or the 41mm Chronograph. Reported prices for these replicas sit between $280 and $900, based on movement and finish.
How the 45mm is measured
Case diameter is measured across the caseback, from the 9 o'clock edge to the 3 o'clock edge, crown excluded. Listings that include the crown or the lugs report 47mm to 48mm for the same watch. Ask the seller for a caliper photo on the caseback. Lug width on the genuine Grande Complication is 22mm. A replica that quotes 20mm or 24mm lugs is a different case.
Movements used
- Asia 7750 chronograph, 28,800 vph, automatic. Runs center seconds and two subdials. Common in mid-tier builds.
- Decorated automatic with faux chronograph modules. Subdial hands move with the time, not with the pushers.
- Hand-wind tourbillon copies. Low volume. Reported prices above $700.
None of these movements match the IWC calibre 79091. The Grande Complication holds 659 parts: a minute repeater, a chronograph, and a perpetual calendar. Replica versions keep the dial layout and drop the functions.
Dial and functions
Genuine layout: perpetual calendar with day, date, month, and moonphase, plus chronograph counters. On replicas the moonphase disc advances once per day from a 24-hour gear, not on a 29.53-day cycle. Push correctors on the case side do nothing on most builds. Confirm which subdials work before payment.
Case, crystal, and weight
Most replicas use 316L stainless steel. The genuine case is 18k white gold or platinum, so a steel replica weighs less. Replica thickness runs 15mm to 17mm. Genuine thickness is 16.5mm. Crystal is sapphire on top tiers and mineral glass on cheaper builds. Single-sided anti-reflective coating is standard. Double-sided coating appears in the higher price band.
Checks before buying
- Request a caseback photo with calipers.
- Ask for a 24-hour time-lapse video to test the moonphase and date change.
- Test both chronograph pushers for start, stop, and reset.
- Confirm crown operation: winding, date set, time set.
- Check the strap. Genuine uses alligator. Replicas ship calf or synthetic.
Limits and legal notes
A replica cannot be serviced by IWC or an authorized dealer. Parts for the 79091 calibre are not sold to the public. Selling counterfeit watches is illegal in the United States under 18 U.S.C. 2320. Customs seizures at US ports run in the thousands each year. Resale value is close to zero.