Originally Posted by Rnlcomp

Yeah the tuner does have a gap in revs/mi, When I ordered my custom tunes I specified stock for tire size.

Are your new tires 2" larger than stock? If so you could request a revision in your tune to that stock spec and then the speedo might be dead on like mine is.

I used IDS to reset mine but there again, my tune was written with the stock size to begin with.
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Originally Posted by Tylerl66

When I sent my info in about gears mods and tire size I stated my new tire size.

So maybe I need to reprogram and instead of manually putting in revs per mile I'll try stock to see if that's it

Originally Posted by Tylerl66

Stock was spot on

Originally Posted by Tylerl66

I just did the same thing in my speedometer is between one and 2 mph off
But from what I learned on a thread the other day is ford sets your speedo to show your going faster than you really are so I'm not complaining

Originally Posted by GetYaFordOn

If this were up to me, I would allow for entering actual circumference measurements into the tuner, and not the indicated size on the sidewall.

You can lose an half an inch in tread height and that translates to a few inches off the circumference that isn't accounted for when setting tuners up.

Originally Posted by jp360cj

From my understanding, when you send 5* your specs (gear ratio, tire size, etc) they program them in the tuner as the "stock" setting.

Originally Posted by GetYaFordOn

If this were up to me, I would allow for entering actual circumference measurements into the tuner, and not the indicated size on the sidewall.

You can lose an half an inch in tread height and that translates to a few inches off the circumference that isn't accounted for when setting tuners up.