[Suberman]

Originally Posted by Td-d

I'm well acquainted with the reasons why cold air allows for greater air-mass, and the functioning of intercoolers - I just really struggled to follow your logic.

The problem with this theory lies in that first sentence - this is not how the Subaru knock strategy works. It's a more reactive process - see here. It's also a curious question as to whether the BRZ is knock sensor controlled, since I suspect every ODB2 compliant vehicle since 1996 is likely to have knock sensors (I stand to be corrected).

I agree that direct injection reduces in chamber temperatures, that's the whole advantage, but DI is not used at all load ranges.

I think DI is always active. The port injection only supplements DI.