The extra-light, all-aluminium engines, together with optimization of the front and rear axles, also contribute to the low total weight. The particularly compact three-cylinder petrol engines weigh around 15kg less than the previous generation of similarly powerful four-cylinder units. Highly unusual in the small-car-sector is the new Corsa’s aluminium engine bonnet, which although longer, saves 2.4kg in comparison to the previous model’s bonnet made of steel. The Insignia flagship was previously the only model in the Opel range with an aluminium bonnet. The seats also have been put on a diet. The new optimized seat structure saves a total of 10kg – 5.5kg at the front, 4.5kg at the rear. New lighter insulating material was used for fine tuning. Altogether the measures result in a weight reduction that, in combination with optimum aerodynamics and the efficient powertrains, will lead to a considerable reduction in fuel consumption and CO2 emissions.
The GSi's engine mapping had been carried out by Opel tuning specialists Irmscher. A model with the 82 PS (60 kW) 1.4 L multi point fuel injected engine, which was otherwise mechanically identical to the GSi, also became available as the Nova SRi in the United Kingdom. In January 1988, a turbocharged version of the Isuzu diesel engine was introduced, with power increased to 67 PS (49 kW).