Can someone please point me to the thread about calibrating tire size and speedometer? I can’t seem to find it for the life of me now that I need read it.

 

Forscan?

 

https://docs.google.com/spreadsheets...htmlview#gid=0

 

There's a thread that's stickied to the top of this 2015 - 2020 Ford F150 subforum.

 

Yep, it is the FORScan thread that links you to the spreadsheet. When you locate the entry in the spreadsheet, read the notes in columns to the right of the 'code'. Read the directions in the speadsheet, and understand how it works before you begin.

ProTip: record the stock entry so when you mess up you can go back to stock sizing and start over.