Hi guys, I have an 07 GT 5spd with MSD ignition, MMR CAI, JBA Shortys, Magnaflow X-pipe & catback, SCT Tuner w/ Brenspeed 93 Octane tune and 3.55's. I'm getting about 15mpg. Does that sound right to anyone? I dont drive it like a granny and am never in 5th gear but all these mods were said to get better gas mileage. I hear people getting 20mpg+ with similar mods. Any ideas? Thanks