But how was Opel/PSA able to shave off so much fat from the hatchback? For starters, all engines will be made from aluminum (-15 kg / 33 lbs), much like the hood (-2.4 kg / 5.3 lbs). The optimized seats (-5.5 kg / 12.1 lbs front and -4.5 kg / 10 lbs rear) contribute to this significant weight loss, while the insulating material used throughout the cabin is also a new weight-saving development. The most important diet is found in the body-in-white, which is a term referring to the body panels being joined together before adding the engine, sub-assemblies, and trim. The new BIW is an impressive 40 kg (88 lbs) lighter than the old one.
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).[8]