Purchase advice Gasoline 5 Series or 6 Series

Hey people I don’t know if the question has already come up or it tells me please. So I’m looking for a 640i or a 530i. My problem is the following. I’ve always driven diesel until now until suddenly a weak petroler. Now it makes me itchy for a petroler with power so from about 250hp up to max 320hp. Due to my daily work distance of not quite 100km a diesel would be of advantage by the consumption. And here lies d he point. I am very spoiled by the diesel from the consumption and therefore where are you fie consumptions in normal driving mode and to what would you guess outside of these two vehicles? Thanks already for your help. MFG StefanpConsumption very spoiled and