What to do???
 

I have a 2007 F-250 Crew Cab 4x4 with the current strategy being VXCF4X3. I have a turbo back MBRP 4" w/o cat and the stock 275/65/20 tires and a SCT with Matt's SRL tune. I am only getting around 13 mpgs and 15 on a highway trip. As for cold starts I have no problems with my current strategy, but it seems to really "drink" the fuel while idleing and I would like to see a little bit more fuel economy. Do I need a ECM rollback and the FICM reprogrammed, or just one or the other? I looked at the order form and was going to wait and see what options I need to do.

Your good with the VXCF4, so no change needed there. You can go with a FICM flash, but you won't see as good of results as some one who had a VXCF7 or VXCF9 would. They would be getting even worse MPG then you do. It should help alittle...but how much I could'nt say.

Times two on what Jeremy said.

The FICM flash may help a little, but probably not as much as one would see if they had a later calibration.