Were I an owner I would improve FE by....

A) "Wiring" the wastegate fully open.
B) Milling the head to get a standard "non-boost" DFI compression ratio of 12:1
C) Design a mod that kept the wastegate fully open except at WOT or with a quick/rapid depression of the gas pedal, sort of a reverse implemenation of BA, Braking Assist. (Not compatible with "B")
D) Design a variable intake valve delay (Atkinson Cycle Engine) such that a 12:1 "off-turbo" compression ratio could be used and then switch back to 10:1 as the turbo is allowed to come online, boost rises.

Note: CAI & BOV are only for those with "boy-racer" mentality and are typically, like K&N, are simply "snake oil" for those that are most gullible.

 

Funny guy you should actually mount them on a car and drive it before you start providing bad information to others.

I have both and a larger TMIC as well. As I remove these prior to dealer visits I can honestly say you are full of it. There is such a difference in the power, responsiveness and top end power with these mods over stock.

With them I can bark all 4 tires with my AWD touring leaving the line. Try doing that stock

 

Please note that the title of this thread is "CX-7 and fuel efficiency".I don't think that relates much, if at all, to how much rubber you can lay down on the roadbed. Most likely exactly the opposite.

 

07 awd gt , 15 city , 25 hwy at 70mph