Car and Driver: The current M3 was fitted with a unique M engine. Will future vehicles be derived from existing BMW engines, or will you continue to afford yourself the luxury of bespoke M engines, like the naturally aspirated V-8 and V-10?
Friedrich Nitschke: At the core of their architecture, our engines will be closer to BMW AG engines. But they will be optimized for the specific needs of M customers, so we can still essentially speak of standalone engines.
So S-engine will be more closer than std. family wagon engine? In other words they will be only chipped and little tuned (bigger cooler and differend plastic cover, just marketing..) , so they cannot handle more than 7000rpm...over 8000rpm like S54 need strenghed parts in engine and more $$$ and less profit to Bmw. Saddly if things going this way
, we will see it when F80 will launched.