No shit, 'putting turbo's on' I'm talking about cars coming factory turbo, this simply won't happen if the straight six is replaced with the v6. Look at past makes and models, only commodore with a turbo was straight 6, as soon as skylines went to v6 no turbo, 300zx was twin turbo and look at the mess they were, then the 350z no turbo.
Performance comes second to handling, emissions, efficiency and safety in modern family cars today. 'Weight is not an issue' listen to yourself speak... Of course it's an issue hence why big family cars are not selling well.