On the Motor Show in Geneva in March
1992 OPEL presented the prototype Eco3.
On the base of the Corsa with the
1.5-Turbodiesel-engine the research car was developed, in order to
show the efforts in fuel and emissions reductions.
With the Eco3 the goal was set to reduce
the fuel consumption of 5.1 liter/100km in the euro mix cycle by 22%
to 4 litres. Therefore extensive changes were made to the drive
train and the body.
The engine of the
Eco3 was based on the turbo-Diesel engine, available for the Corsa
for the '92 model year. The engine modified for the Eco3 had a power
of 53kW/72PS at 4600RPM. The maximum torque was 143Nm at 2600RPM
In order to obtain
the focused fuel consumption values, the following technical changes
were made:
- reduction of the
oil pressure
- use of synthetic
oil in engine and transmission
- installation of an
automatic start/stop device, which switched the engine off in idle.
To restart the engine, the accelerator pedal had to be pressed
slightly
For a better
efficiency of the engine, an air cooler was added, whereby an
increase of the power and the torque were reached.
A further reduction
of the fuel consumption was reached by modifications on the
transmission. The final ratio was changed from 3.74 to 3.42, and the
fifth gear from 0.71 to 0.63.
As aerodynamic drag
has a substantial influence on the fuel consumption, particular
attention was paid to the rolling friction and the air resistance.
For the Eco3
friction-poor radial tires were used, which were developed together
with Goodyear and which were already used on the research vehicles
Impact und Eco2. Due to the special tread and rubber mixture the
rolling friction was reduced by 50%.
The aerodynamics were
improved by body modifications, so that a drag coefficient
(cw-value) of 0.33 could be reached. The following changes were
done:
- modified rear
bumper with lateral outline edge for the air flow
- larger front bumper
with 40mm rubber lip
- side skirts
- optimization of the
outside mirrors
- flushed wheel
covers
- removing of the
gutter rails
- lower the car by
8mm
