Your dealer is wrong. Ford took away the ability for the dealer to do this on newer trucks. I believe that started with the 2015's.

 

 

Crazy, isn't it.... Not sure why Ford took this away. I once heard a story about a guy who special ordered a King Ranch with a different wheel and tire combo than what would normally come on it. When it arrived, the dealer had screwed up on the order and it didn't have the proper wheel and tire. The dealer acknowledged their mistake and ordered the requested wheel and tire combo. It wasn't until they installed it that they realized tire size is set at the factory with no option for the dealer to adjust it in IDS anymore. I do know of a dealer who has been known to use Forscan occasionally, but that is obviously a bit of a liability for them.

 

Ford had no choice but to remove this parameter. The vehicle was certified to meet emissions and EPA mileage estimates based on the As Shipped configuration. If the dealer was allowed to change these parameters, the vehicle may no longer be in compliance - even if the configuration was available on the same MY vehicle.

 

I had two Ford dealerships tell me they could do it. One priced me at $110 and the other one priced doing it at $65. Said it would take about an hour to do the programming.
I am however going to check it first with a gps and see how far off it is before I make the decision to have it done.

 

They must not do many. They are both going to be pretty surprised when they realize they can't.

 

those are 2 dealerships I would steer clear of because obviously, they are clueless about reprogramming the speedometer on 2015 and newer F150s.

This is what prompted my question at the beginning of this thread.

 

Here's a few links if interested in FORScan correction for the speedometer. Very helpful, and got me to a 1/2 MPH error at 60MPH, checked against 2 separate GPS readouts. Thanks to the members who figure out and post such helpful information. KM
Ford built as Tire Calculator
Correct your speedometer error