Corsa Eco3 Studie

Corsa Eco3 Prototype

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