Hmm, I just get the intake silencer off 2 weeks ago.

I discover that my wrx reach over 300 miles/14 gal by the first tank of gas. I don't believe my eyes, so I tried another tank of gas.

Unbelieveable!!! I used up the second tank and I get also 300 miles/ 13.5gal.

Is that real I could get more miles when the intake silencer removed?
Before the silencer still in my car, I get at most 260 for 14 gal.

ANYONE HAS SAME EXPERIENCE?

 

Before and after snorkel removal, I typically get 305-310 miles to a tank (13.5 or so gallons), this is from a normal week of commuting and errand running. I can drive the car harder and it does return worse mileage. Or if I sit on I-5 at steady throttle position for hours, it returns better. I doubt the snorkel will effect mileage as much as your driving style.