Originally Posted by tuned2ride
That's a pretext. Because they COULD build a 184HP I6 DI NA 2.2-2.5 with no worse fuel economy / CO2 emission and as quick in 0-100km/h.... it is not a technological issue but the nonsense current Euro fashion /trend would kill it, for bad reasons (like displacement vs registration fee) irrelevant to us , in North America.
Good post. In reality it has to do with the US crash-test regulations too. For the US market, every drivetrain configuration has to be crash tested. So if BMW were to add the magical small displacement I6 you and I think they should, they'd need to crash test the automatic and manual transmissioned variants of the F30 chassis with a NA I6 in it. With the de-tuned N20 in the 320i, since it is the same engine block, there is no need to crash test the F30 320i chassis. However, for a car company such as BMW that charges an outrageous amount for it's cars, you'd think they could afford to add such a model to the US lineup.