Good luck with that 30+ MPG stuff. I have K&Ns and a magnaflow exhaust (breathes better in and out) and I do not get 30+ MPG ever... and in the city, if you drive with a lead foot, expect somewhere in the 17 range realistically. Not trying to be a buzz kill, but I can expect a 16 year old with a 6 spd XF to get $hitty MPGs