Bill hits the TS right on most of the time with the custom tunes.
In my case the tires I have are lower profile.
To much squish was taken out.
So instead I opened up custom options and added to the TS.
No big deal.
Your speedo needle will always read 1-2 mph higher»that's the way ford designed it.
Best way to dial in your TS is with adjusting the number in the gryphon using a gps.

Sounds good, Thanks for the info!

An to add to what 88 said, the easiest way to get your tire size correct is just driving for a while after clearing the odometers and using this simple formula.

Truck odometer/GPS odometer x current TS= New TS

Since you are using the odometer you dont have to try matching a number on the GPS with a number on the programmer or truck. To make the calculation more precise drive at least 10 miles. The further you drive the more exact the percentage will be when you multiply by the tire size.

You can even apply Longshot's excellent approach without a GPS. The mileage markers on an interstate are quite accurate. If you drive a measured distance using the mileage markers, you can divide your truck's odometer reading by that, instead of a GPS value.

The farther you drive using either approach, the more accurate your correction will be.

- Jack

I modifed the tyre size while choosing towing program and got this:

Gryphon (74) Speedo (80) GPS (70)

I couldnt stand the changes of the Towprog over the stock, alot of droning and noise! :confused:

I hope my pre ordered custom tunes wont have this issue :(

You need to fill out alot more info in your user cp.
It's required info, like hex and serial number that's not entered yet.

I have updated my CP (without the serial, im abroad right now)

Hopefully when your custom tunes get done that tge droning noise will be muffled.
Have fun studying abroad!:)

Yea that's what Corey told me :)