Alfa Romeo will debut Fiat Powertrain's
innovative new "TCT" gearbox, the latest
automatic dual dry clutch 6-speed
transmission that is part of the modern
family of 6-speed gearboxes (C635), on the
MiTo in Geneva next week.
will debut Fiat Powertrain's innovative new "TCT"
gearbox, the latest automatic dual dry clutch 6-speed
transmission, coupled to the Start&Stop device, on the
MiTo on the occasion of the 80th Geneva Motor Show next
and produced by FPT, Fiat Powertrain Technologies, this
new device is part of a modern family of 6-speed
gearboxes (C635) that was launched - in the mechanical
version - on the 170 HP MiTo 1.4 MultiAir Turbo petrol.
Now it's the turn of the “Alfa TCT” teamed with MultiAir
engines with Start&Stop system fitted as standard:
indeed, the Alfa Romeo MiTo is the first car on the
market to combine these three innovative technologies.
Available from next spring, visitors to the show will be
able to admire a 135 HP MiTo 1.4 MultiAir Turbo petrol
with “Alfa TCT” and gear levers incorporated into the
steering wheel (optional).
The new device, conceptually, consists of two gearboxes
in parallel, each with its own clutch, which allows the
selection and engagement of the subsequent gear while
the previous one is still engaged. The gear is therefore
changed with a simple gradual switch of the
corresponding clutches, guaranteeing continuous torque
delivery and therefore traction. The result is a driving
comfort and sporty feeling well above those offered by
conventional automatic transmissions (with torque
converter), as proven by greater speed of gear shift,
the possibility of selecting between manual or automatic
mode and a near-zero power loss during the gear change.
In addition, the purchasing, servicing and running costs
are limited, while fuel consumption is reduced, thanks
also to the implementation of the Start&Stop system, up
to 10% less than a traditional automatic hydraulic
transmission with torque converter.
Specifically, the “Alfa TCT” features the largest number
of interactions with the vehicle's systems available on
the market. Indeed, its operation interacts with the
steering wheel, the brake and accelerator controls, the
Alfa DNA selector, the Start&Stop system, the ABS, the
engine and the inclinometer (slope detector to engage
the Hill Holder and disable Start&Stop on activation).
Other peculiar features of the new “Alfa TCT” are its
flexibility of application, thanks to the compact size
of its components, and the fact that it is a dual dry
clutch (the type of clutch that guarantees the highest
degree of efficiency in terms of fuel consumption among
all automatic transmissions). If we compare "Dry"
clutches with oil bath ("Wet") ones, we can safely say
that the former dissipate energy only during the actual
slipping phase of the gear change and on pick-up,
whereas wet clutches, which always operate in an oil
bath, introduce losses due to viscous friction such as
those of conventional automatic transmissions even when
they are not in operation. What's more, they require
forced cooling with oil and therefore continuous energy
expenditure to drive the dedicated oil pump (absent in
the case of "Dry" clutches). Moreover, a "Wet" automatic
transmission requires approximately 4.8 litres more oil
than the "Dry" version, again for reasons of clutch
cooling (in this way, weight is added and losses due to
splashing increase). When all these effects are added
together, a “Alfa TCT” is found to be approximately 6%
more efficient than the corresponding "Wet" one in terms
of consumption. Last but not least, the advantages of
the "Dry" clutch include the lower cost and the
increased ease of installation.
Lastly, it should be remembered that the new “Alfa TCT”
boasts a generous 23 public patents split into 3 areas:
gearbox control, gearbox mechanics and gearbox actuator.