Originally Posted by Famine
There are alot of people doing gear swaps that can't get the xcal to change the gears in the options menu right now. Speedos aren't accurate until sct can fix the issue.
I have no problem with my X4 changing the revolutions per mile on my 15 Ecoboost. My winter tires are taller than my summer tires and I change the revolutions per mile when I swap tires. It will work for gear changes to, just figure out the circumference of the tire (will be in the specs at Tire Rack) and increase or decrease the number by the percentage change in your rear end gear ratio.