Porsche Cayman User Handbook Manual page 40

If you want to get straight to the point,
you don't take any detours.
Transmission.
Porsche Doppelkupplung (PDK).
The optional Porsche Doppel-
kupplung (PDK), with both manual
gearshift and an automatic mode,
enables smooth gear changes
with no interruption in the flow of
power. This results in significantly
faster acceleration and lower
fuel consumption, without having
to sacrifice the ease of automatic
transmission.
48
In total, PDK has seven gears
at its disposal. Gears 1 to 6 have
a sports ratio and top speed is
reached in 6th gear. The 7th gear
has a long ratio and helps to
reduce fuel consumption even
further.
PDK is essentially two half gear-
boxes in one and thus requires
two clutches – designed as a
double wet clutch transmission.
This double clutch provides an
alternating, non-positive connection
between the two half gearboxes
and the engine by means of two
separate input shafts (input shaft
1 is nested inside the hollowed-out
input shaft 2).
The flow of power from the engine
is only ever transmitted through
one half gearbox and one clutch
at a time, while the next gear is
Cayman S