By DAVID PIKE

On release in October 1981 the VH Commodore was offered to the motoring public of Australia as a much-improved version of the VC model which it replaced, even though visually the car looked very similar to the previous model. Early model Commodores were based on GM Opel designs and in Europe car manufacturers tended to concentrate on steadily improving existing designs rather than adopt the American approach of making major body and appearance changes in each new season model.

The most significant change to the VH was in the smaller engines. Both the 1.9-litre four cylinder and the 2.8-litre small six received air injection for better combustion. In the four this was achieved by Pulsair whilst in the six an air pump was introduced along with spark control. This feature resulted in markedly improved fuel consumption from both engines. In the manual four a 12.5 percent improvement was claimed whilst in the six the figure was 14 percent. A five-speed manual transmission was also offered for the first time as an option on the 1.9 and 2.8-litre engines. Modifications to the engine mounts reduced noise and vibration transfer to the cabin.

The other engines remained as before and with these the manual gearbox remained as the four-speed since the new Borg-Warner five-speed units weren't suited to the torque of the bigger engines. The 5.0-litre V8 engine was also offered for the first time as an option on the station wagon. In addition the automatic transmission on the 5.0-litre was changed from an American Turbo-Hydramatic to an Australian Tri-Matic.

To make the VH Commodore look a little different from its predecessors a revised grille and new front guards were fitted. These panels were designed in Australia and with them the Commodore moved away from the shape of the German Opel.

At the rear end the tail-lights acquired small louvres but otherwise the car looked like earlier Commodores. In an attempt to increase the differentiation new exterior paint colours as well as changes to interior trim were introduced. In the SL/E top model a new super-luxury leather trim and a Shadow-Tone option pack in the new paint colours gave a decided lift. With the VH the base model was badged as an SL, the former SL designation was changed to SL/X and the SL/E designation was retained for the top of the range.