I know this is an old thread so I'm hoping maybe the process has changed. I've got a larger size tire than stock now and there is a local shop that says they can change the revs per mile using an HP tuner to fix the speedometer inaccuracy.

Can anyone confirm that this will work?

Thanks

(2015 Ford F-150 4x4 Lariat for reference)

 

Yes HPTuners will do what you’re wanting. You do it using the VCM scanner vs the actual Editor software, so they don’t have to spend credits and license your vehicle. Once you own an HPTuners device, making speedo and gear change calibrations are essentially free. I wouldn’t pay too much for this service. If you were close by, I’d do it for free.

 

Thanks! I appreciate it. Unfortunately I'm in Alabama. The local guy quoted me around $100.

 

Or you can use Forscan and if you already have an OBD2 connector it won't cost a penny.

 

I have an SCT X4 that I used on my 2014 3.5 EB. I updated all the firmware on it recently and tried to change tire size on my '19 3.5 EB. The option isn't there. Bummer. Guess I'll have to get a tune from 5 Star with tire size included.

 

FORScan software is free, an OBD cable is under 20$ and once you get over the semi-tedious process of backing up all of your as built files any change possible via FORScan can be made in about 5 minutes.

VINT-TT55502 is the cable I bought on amazon

 

I went from stock to 275/70/R18s.

Did this with mine, worked like a charm.