hey guys i got a 2006 mustang gt, 67k miles, saleen stage 2 blower with 3.4 pulley, not cats, mac axle backs, 20in staggered wheels, and a bbr tune, other than that car is stock. iam 12mpg high way or town. is this normal. i get about 180 miles on the tank. this is horrible i do not have a heavy...