With no change in driving habits, it dropped MINE. Can't say what it will do for others based on terrain, driving commute, etc. What works/doesn't work in Western PA may be the opposite in Oklahoma, for instance. I did see increases with the drop-in, so assuming all other variables remained the same, the only difference was the SRI/CAI.
Hand calcs were quite close, so I have confidence in the numbers. I'm at around 16.7K mileage wise since February when I bought the car.