I have made the decision to keep my '03 4.6L Expedition with 154K miles and spend some money on upgrading and updating; I am not paying what Ford wants for a new Expy and I figured I would be happier with keeping and upgrading my '03. The motor and trans are both in excellent condition so I tossed the OEM clutch fan, intake and exhaust manifolds and installed electric fans, underdrive pulley kit, shorty headers, 4.10 gears and purchased the 5 Star tuner. The 5 Star price included three tunes and I am running the most conservative of the three.
I wish I could justify the expense of a dyno pull to measure the increase in performance and I might do that at some point but right now I am just enjoying the results which register strongly on the butt dyno. I can't tell you how much of the increase can be attributed to the tune but I can tell you that without the tune, the results would have been very different. 5 Star was easy to work with, very professional group.