Tudor enters the GMT category
For most of its history Tudor relied on third-party automatic movements (mostly ETA bases) and built its identity on the relationship to Rolex. Starting in 2015 Tudor began deploying its own manufacture-grade calibers via the new Kenissi facility in Le Locle. The MT5652, launched at Baselworld 2018 alongside the highly anticipated Black Bay GMT ref. 79830RB (the "Pepsi" with red-and-blue bezel), was the first Tudor in-house GMT caliber.
True GMT (jumping local hour)
The MT5652 implements a true GMT: the local hour hand can be advanced or rewound in 1-hour jumps via the crown without disturbing the running of the watch or the position of the GMT (24-hour) hand. This is the same architecture as the Rolex 3186 in the GMT-Master II: useful for travelers who want to change time zones without resetting their watch. The 24-hour hand reads the second time zone via the rotating bezel; the local hour jumps in 1-hour clicks; the date jumps with the local hour as it passes midnight in either direction.
Kenissi family architecture
Mechanically the MT5652 is part of the Kenissi MT5xxx family: 4 Hz, 70 h reserve, silicon hairspring, free-sprung balance with variable-inertia regulation, and COSC chronometer rating. The architecture is shared with the MT5612 (Pelagos) and MT5402 (Black Bay 58); the GMT module is added on top of the same base train. Like the rest of the Kenissi family, the MT5652 is also supplied (with appropriate finishing changes) to Breitling and other licensees.
Black Bay GMT and the Pepsi factor
The Tudor Black Bay GMT ref. 79830RB launched at Basel 2018 at retail of approximately USD 3,900, with red-and-blue ("Pepsi") aluminium bezel insert, snowflake hands, and the MT5652 inside. It became one of the most-anticipated and most-discussed Tudor releases of the decade, partly because Rolex did not offer a steel "Pepsi" GMT-Master II at the time (the steel ref. 126710BLRO came one year later in 2019). The Tudor Pepsi at $3,900 was effectively the only easily-buyable steel GMT Pepsi for nearly a year, driving heavy demand and waiting lists.
Variants and successors
The MT5652 family has expanded since 2018: the Black Bay GMT S&G (steel + gold, 2021), the Black Bay Pro ref. 79470 (2022, Explorer II-style fixed 24-hour bezel), the Black Bay 58 GMT (2024, smaller 39 mm case with the same MT5652 caliber). All use the MT5652 base architecture. The MT5652 currently sits as Tudor's only in-house GMT caliber and the engine of the brand's entire travel-time offering. The Kenissi family is also the source for the closely-related Breitling GMT calibers in the Premier and Superocean Heritage GMT references.
