Hands-On: IWC Portugieser Hand-Wound Tourbillon Day & Night

After several years of leaning heavily on its flagship Pilot’s collections (and one outlier year in which it went more or less all-in on the major revamp and relaunch of the Ingenieur), IWC trained the spotlight back on its Portugieser collection in 2024, introducing a whole slew of new models from basic three-hands to chronographs to high complications, the highest of which was the absolutely unprecedented Portugieser Eternal Calendar, perhaps the horological highlight of this year’s Watches & Wonders Geneva fair, which featured a moon-phase complication designed to be accurate for 45 million years.

So dominant was the Eternal Calendar in the “Best of 2024” conversation that some of IWC’s other high-horological creations in the new Portugieser lineup may have been largely, and unfairly, overlooked. Chief among these is the timepiece I delve into here, the Portugieser Hand-Wound Tourbillon Day & Night, which marks both the debut of a new execution of a classical, calendrical complication and the latest foray into an exclusive precious-metal alloy. 

The case of the Portugieser Hand Wound Tourbillon Day & Night is forged from IWC’s proprietary Armor Gold, introduced back in 2020, a gold alloy that the Schaffhausen-based manufacture says is significantly harder and more wear-resistant than the traditional 5N rose gold that it closely resembles. (Its composition is actually 75 percent pure gold, with the other 25 percent being an alloy of undisclosed materials.) The case measures 42.4mm in diameter and 10.8mm thick, resists water pressure to 60 meters, and is mounted on a curved, black alligator leather strap from Santoni, an Italian purveyor of footwear and luxurious leather accessories that has long partnered with IWC. The strap fastens to the wrist with a folding clasp also made from Armor Gold. 

The dial, under a convex, antireflective sapphire crystal, is made of lacquered obsidian, with a finely polished finish and gold-plated details, including the applied Arabic numerals and the leaf-shaped hands that are characteristic of the Portugieser family. The most noteworthy dial elements, of course, are the ones that give this timepiece its lengthy moniker. One is the large aperture at 6 o’clock offering a view of the flying one-minute tourbillon, which consists of 56 individual parts and weighs only 0.675 grams. Containing the balance wheel and balance lever inside its tiny cage, the tourbillon makes a complete rotation on its axis every 60 seconds. This constant motion of the movement’s oscillating system was originally designed to counteract the effects of gravity on the accuracy of a pocket watch’s movement; in the modern wristwatch era, it’s more of a dynamic mechanical showcase for the eyes than a technical necessity, but it’s very much a visual treat as well as a technical coup for IWC’s watchmakers. Improving the flow of energy to the movement, as well as contributing to its impressive 84-hour power reserve, is the “Diamond Shell” process applied to the pallet lever and escape wheel, which are made of silicon and treated with diamond coating for increased friction resistance. 

Joining the tourbillon in its own, smaller aperture at 9 o’clock is an ingenious day-night indicator dreamed up by one of IWC’s former watchmaker trainees named Loris Spitzer. Its primary element is a small, three-dimensional orb with a dark side and a bright side, representing a planet in daytime and nighttime hours, which makes a complete rotation once every 24 hours on its own axis in synchronization with the passing of daytime to nighttime and back again. Since the movement developed for this watch, IWC’s Caliber 81925, is manually wound, and thus lacking an oscillating weight for automatic winding that might have gotten in the way, this tiny globe is visible not only from the front view of the watch but the rear side as well, thanks to an additional sapphire glass in the caseback. The movement also boasts a partly skeletonized, gold-covered baseplate (the barrel is visible behind it) and a host of decorations, including a circular côtes de Genève pattern on the bridges.

The IWC Portugieser Hand-Wound Tourbillon Day & Night  (Ref. IW545901) carries an MSRP of $79,300.