Fiat ‘Topolino’ mules have recently
been seen testing in around Turin; the tiny new car will be significant not just
for returning Fiat to the sub-A category, but also for marking the debut of the
revolutionary new 900cc twin-cylinder gasoline engine designed by Fiat
Powertrain Technologies.
Dubbed the spiritual successor to the
1936 ‘Topolino’ (Little Mouse), this new urban micro car is
designed around a shortened version of the ‘Mini’ platform
that underpins the Fiat 500. It will be about 40 cm shorter,
at around 3.15 meters, and thus marginally longer than the
forthcoming Toyota iQ, which is just under 3 metres.
However, the new SGE engine will allow Fiat’s engineers to
package it in the rear of the car, something that Toyota and
VW’s up! have failed to achieve with their front-engined/front-drive
layouts. This is expected to leave the Topolino with a
decent luggage space under the bonnet and a slim, but
useful, boot area above the engine.
The prototypes seen out testing clearly
reveal a cut-about 500 platform and the rear positioning of
the new engine. The SGE (Small Gasoline Engine) will be one
of the most significant power units to be developed by Fiat
Powertrain Technologies (FPT) in recent years. In the
photos, the SGE unit’s presence is betrayed by the tiny
exhaust pipe. The story of this engine can be traced back to
the early months of 2007, when bench and in-vehicle testing
was completed on the first 700cc two-cylinder engine
prototype. In tests that focused on assessing the engine’s
performance potential, the prototype achieved a peak output
of over 80bhp, and significantly, demonstrated that it can
significantly reduce fuel consumption whilst achieving low
noise, vibration and harshness.
On the basis of these test results, plans
were made for a family of both naturally-aspirated and
turbocharged two-cylinder engines, whose production
displacement (900cc) will be chiefly suitable for A-segment
vehicles. These new engines will use Multiair technology and
will be available both in petrol and dual-fuel natural
gas/petrol versions.
The SGE unit will make its world
production debut in the Topolino when the new car is
unveiled at the Geneva Motor Show in 2010. Pre-production of
the SGE is expected to commence in the autumn, around five
months before the Topolino is launched. In addition, FPT is
working on a hybrid system for the SGE, which mates an
electric motor/generator to a dual-clutch
transmission. Helping to package the engine in the back of
the Topolino, a new space-saving integrated inlet manifold
that has been developed in anticipation of the future hybrid
version.
