Stage 1+SF Cobb tune My daily driver so I don't wanna kill my car... So I put in SF Cobb intake\airbox and it sounds like an angry rattlesnake is hissing in my car. I lost 5 MPG. I'm surprised because I heard this thing would not make a difference. It has.... My car has a deeper roar and has more/smoother acceleration. Anyone else experience a significant loss in gas mileage?