Originally Posted by DerekJohnScott
Generally it is either horsepower or mileage. Just sayin'
+1. There are a few exceptions but they are usually small things, like a cold air intake will give you a few ponies and maybe 1-2mpgs. But once you get into the big stuff like heads, cam, intake, ect mileage goes out the window! But "what kind of gas mileage does it get?" sure as hell didnt come out of my mouth when i bought my stang