The dealer is limited to programming it to sizes that came stock.
I doubt any 07's came with 25.7" tires, but maybe I'm wrong.
Here's a llist of 25" sizes:
165/80R15 = 25.4X6.5R15
195/65R15 = 25x7.7R15
195/70R15 = 25.7x7.7R15
205/65R15 = 25.5x8.1R15
215/60R15 = 25.2x8.5R15
225/60R15 = 25.6x8.9R15
265/50R15 = 25.4X10.4R15
275/50R15 = 25.8x10.8R15
135/90R16 = 25.6X5.3R16
145/80R16 = 25.1X5.7R16
195/60R16 = 25.2x7.7R16
205/60R16 = 25.7x8.1R16
215/55R16 = 25.3x8.5R16
225/55R16 = 25.7x8.9R16
245/50R16 = 25.6x9.7R16
265/45R16 = 25.4X10.4R16
275/45R16 = 25.7x10.8R16
315/40R16 = 25.9X12.4R16
135/80R17 = 25.5X5.3R17
145/70R17 = 25X5.7R17
155/70R17 = 25.5X6.1R17
205/50R17 = 25.1x8.1R17
205/55R17 = 25.9x8.1R17
215/50R17 = 25.5X8.5R17
225/45R17 = 25x8.9R17
225/50R17 = 25.9x8.9R17
235/45R17 = 25.3x9.3R17
245/45R17 = 25.7x9.7R17
255/40R17 = 25x10R17
265/40R17 = 25.3x10.4R17
275/40R17 = 25.7x10.8R17
295/35R17 = 25.1x11.6R17
315/35R17 = 25.7x12.4R17
So, using an aftermarket Tuner is probably your best bet.
Here's a place to start:
https://www.tactrix.com/index.php?option=com_content&view=category&layout=blog&id=36&Itemid=58 if you have a SUBARU. Didn't see any support for Fords. Anywhere. Some TALK about it here
http://www.focusfanatics.com/forum/showthread.php?t=254388 but my gut thinks you need a different tuner, not just that interface and a program. I've been wrong before though.
FWIW, I went from 245/75-16" (30.5") down to 235/65-16" (28") and my speedometer correction is manageable. When I indicate 70, I'm only doing about 65 or so. My SOP is to drive 5-7 over and it keeps me just about right.
Depending on your stock tire size, which you did not post, you may get by with no correction really needed. If you have an Automatic transmission, your shift points may not hit where you like them, since the PCM programs shifts to speed.
http://www.hypertech-inc.com/products-speedometer-calibrator.aspx is another option, scroll all the way to the bottom.
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