It seems like the trend is to use 4-cyl turbos to replace inline-6 for the new Bimmers across the board. Some people claimed that most manufacturers had to meet emission requirements so they reduced the engine displacement to achieve that. Well, that is not convincing because it's clear the Porsche 718 Spyder is new and it's 4.0L naturally aspirated. How did Porsche get pass that hurdle if emission has to do with engine displacement. Direct Injection is another sore point where the PCV poops onto where the intake valves: thereby, stirring up the idea about eating where you poop. Sooner or later, the intake valves are all going to get choked up. Anyone know how BMW is solving these problems?