I have factory 17's on my truck. I am contemplating 20's. My question is: When I switch to 20's, does the computer automatically recognize and adjust? Or do I need to go to the dealer or buy a programmer? Now, stick with me. Say I get a programmer and make the adjustments, how can I reset to factory settings when those settings are for 17's...taking into consideration that I added other mods before getting the tuner?

 

I am new to the tuner category, but the settings for wheel/gears is to ensure the speedometer reads accurately and gives an accurate odometer reading over time.

I will let others chime in on the specifics of mods however....

 

If the tire height is the same, the speedometer will read the same. Otherwise the dealer should be able to change it for you for a small fee, possibly free if you do lots of business with them.