Probably either a ZF EcoLife 6AP1700B, 6AP2000B, Ecomat 6HP604C
(unlikely) or a Voith DIWA884.5 since these gearboxes are capable
of handling 1800Nm of input torque.
I would guess a ZF EcoLife 6-speed gearbox as SMRT has preferred
ZF gearboxes (as seen in the NL323Fs). I really hope it's the
EcoLife though, as the Voith can sound very boring and doesn't seem
to have acceleration as good as the ZF.
If the full torque rating (1800 Nm) is to be utilised, the only
two gearbox options would be the ZF 6 AP 2000 B (EcoLife) or Voith
D884.5/D884.6.
Remember that just because an engine is rated at 360 PS / 1800
Nm doesn't mean that the full load power / torque is available in
all gears and under all conditions. Modern gearboxes reduce
the torque of the engine in lower gears in order to preserve ride
comfort and to ensure longevity of components. Articulated
buses also have turntables with sensors that progressively signal
the engine control unit to limit the torque of the engine depending
on the angle of articulation.
