Saab and GM vectra

I don't know the exact number, but yes, it was made lighter, have less oil in the oil pan, have lower friction piston rings, have lighter valves (reduced diameter on valve stems), etc. All with the goal of reduced fuel consumption. However, the lower friction piston rings increases the blowby gasses and stresses the crankcase ventilation system. The oil also gets poluted with the blowby gasses and as the total oil volume was reduced the life of the oil is also reduced. Damages to the engine is not unheard of after using non-synthetic oil, have a blocked crankcase ventilation system and delaying an oil change.

The lower friction piston rings presumably have other advantages for limiting the engine wear. The engine B202S in my 1993 2.0 lpt is an amazing engine, fuel consumption is helped by not having the balancer shafts and the high gearing. I regularly do 40mpg on motorway commuting at 60-70 mph. I recently changed air filter, that also helped. The engine is still smooth at 96k miles, in fact the regular motorway driving has made it even better.