Have 275/60R20 KO2 on order, my biggest reluctance to going with a 65 is the speedometer difference. What is the most cost effective way to change the tire settings on the truck?

What should I know warranty wise before doing something like this?

 

Ford disabled the dealer calibration option for this generation of trucks. You'll need to buy a calibration unit for about $230. It flashes the computer with your new tire size and lets you restore to factory if needed. This unit doesn't mess with your engine. My local dealer recommended it and told me not to worry about the warranty unless you try to add 90hp

 

I went with stock size KO2 275/65/18's on my xlt. Had them dealer installed. I was worried about speedometer accuracy. Turns out my factory set speedometer is a few MPH fast. Using the next size tires would have actually made it closer. If you already have your truck, check your speedometer first. Maybe the new tire size would improve accuracy.

 

For $230 you could speed by a cop and then have him tell you how fast you went.....

 

https://www.supertruckusa.com/ford/h...016-ford-f-150

PM SuperTruckUSA for better price

 

It's a scaled inaccuracy. The faster you go, the more it's off. It's not as simple as remembering "-5mph". Depending on what you do it could also mess up your shift points.

 

But it is as easy as remembering 5%

 

Might as well do a Tune at the same time. The SCT tuner should allow you to make the tire size correction when uploading a tune to correct the speedometer.

 

Unfortunately, I don't belive that is correct. Ford made changes to the 2015 / 2016 where you can no longer adjust tire/gearing with the SCT. Kahdir posted a link already to the only product I'm aware of that will enable the change. For me personally, it's not worth the $200+.

Livernois offers the same product:
http://www.livernoismotorsports.com/product/HYT742502

 

I called some dealers today and some told me $140-170 while others told me Ford wont allow the 2015 2016 to be calibrated.. I wish I could get clear answers about if they can do it or not haha. I might stop in on Friday and get a better idea.