Hard to say. Since I have had the CAI installed I have yet to get a tank done without the wife taking the car somewhere boosting it all the way with her lead foot killing the mileage.

I think it may be about 1 mpg better if you can keep you foot from making the cool noise.

 

Have you put a stopwatch to the beast with the mods? I wonder what the 0-60 time is now.

 

It does not seem to have boosted mileage. But makes it easier to drive lighter as you can hear the turbo starting to kick in so you can learn how light to drive it to keep it from doing that. On the down side is the cool sound makes you want to push it so you can hear it.

I cannot wait to get the the BPV on this so it will make more cool turbo sounds.

Note the CP-E ECU reflash to give you 100% throttle control is now available and two users report a large jump in mileage as a side affect. 30 mpg ish....

I am following it with interest but as I live in Smog Check California I cannot do this for fear of not passing smog.

 

My Mileage has remained about the same.

I do find it easier to not spool up the turbo as you can hear it start around 2300 rpm.

Cool noise just begs you to boost it though which is bad for mileage.

I just ordered my Forge BPV....


Downside is my wife keeps informing me it sounds like it is flushing.....

It is fun to boost in next to someone with their window down. You get some really odd looks...