Cal. 3285 is the current GMT and date movement from Rolex. Part of the updated Chronergy family, it features 3-day power reserve and many new components. Cal. 3285 first appeared at Baselworld in 2018 in the GMT-Master II, Ref. 126710. It replaced the Cal. 3186 in most applications.
- Rolex GMT-Master II (2018-present), Ref. 126710, 126711, 126715
This movement is described by Rolex as a “Superlative Chronometer.” The company uses this term to indicate their most accurate modern movements. They claim that these are twice as accurate as any official chronometer certification, to -2/+2 seconds per day “after casing.” The Superlative Chronometer test is performed in-house and goes beyond COSC procedures.
Rolex introduced the Chronergy family in 2015 with Cal. 3255, an updated movement for the famous Day-Date (President) model. It is a major redesign, with Rolex claiming that over 90% of the components are redesigned or all-new. The marquee feature for consumers is the “3-day” (70 hour) power reserve, which is made possible by the “Chronergy escapement” with optimized gears and lubricants as well as a longer mainspring inside a thinner barrel. Other notable features include more efficient automatic winding, unrestricted calendar correction, and “backward” (counter-clockwise) time setting.
The movement can be manually wound with the crown in position 1. Rotate the crown clockwise to wind the mainspring.
The date wheel is advanced along with the independent 12 hour hand, forward or backward, with the crown in second position (one notch out). Set the hour hand to the local time and date, leaving the 24 hour hand showing “home time”.
The time is set with the crown in third position (pulled all the way out). Rotate the crown counter-clockwise to advance the minute and hour hands and clockwise to turn them backward.