I don't understand why people want to second guess the OEM engineers when it comes to something as complex and with so many unknown details as an engine. Only they know what's done to the engines before they're put into the cars, and if they recommend something and back it up with a warranty, why are you going to try to undo everything
Makes no sense.
It's not like an aero mod where you put a skirt here, put a cover there, it's a freaking engine that's worth more than any other part on the car.