I have ordered an SCT X4 from Stage3Motorsports. I plan to use the 87 and 89 performance tunes because I can only get 87-88.5-90 octane gas in Anchorage. I have no idea how it will all work out. I think I'm going to upgrade the plugs first to see if I can ever get the advertised MPG with properly gapped plugs, and a CAI. I was one of the lucky people that get 12.4 MPG in town. For the life of my truck I've averaged 14, but I do get from 20-25 with cruise control on the highway. I guess I figured since my MPG in town was so bad, and since Ford gives absolutely zero f---s about it, that I might as well tune it up as much as I can. I'll let everyone know how bad I screw it up after some mods.