The white dialed, automatic Autavias (known as "Sifferts") were made with both the Cal 11 and the Cal 12 movements. Earlier ones (marked "Chronomatic" or with polished steel hands) used Cal 11, and then Heuer switched over to Cal 12 for the later ones (brushed steel hands). I am not certain what the correlation is between the change in hands (polished to brushed) and the change in movements (Cal 11 to Cal 12), and I would guess that either of these versions might have come with Cal 11 or Cal 12. The very early ones ("Chronomatic") would have used only the Cal 11.
Jeff
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: Was the Siffert Autavia ever made with a
: caliber 12 movement, everything that I've
: seen has had a caliber 11 and all the
: listing tables on "On The Dash"
: list caliber 11. I saw the watch on ebay,
: check the link below.