hey guys, just ordered me a superchips 3842 for my Christmas present,lol, I haven't received it yet, I know I should have contacted hemi fever, but, I wanted the speedometer calibration so I chose the superchips..
my question is about the speedo calibration, it only adjusts by tire size like 22" up to 40+ inches and cant type in the axle ratio?? I've swapped my 3.55s to 4.56 and 31" tires to 33" tires, so??? what size tire would I need to program in to the tuner? its not gonna be 33s that's for sure!! im thinking a 40" tire is what ill have to program in? does that sound right??

 

Try it and see. Use an app on your phone with a gps and check. Then adjust the setting accordingly.