Ive looked through all the old threads so I apologize in advance for bringing this subject up again but it got confusing reading through all that. I just installed my Edge and one of the main reasons I purchased it was because I changed my wheels/tires from the stock 255/65/17 to OEM 275/55/20 with stock gear ration of 3.55. I wanted to correct my speedo etc... So I rolled the truck one full revolution, measured and converted into mm. I got 2503 mm. Do I also need to change my gear ratio? If so, does anyone know what the new ratio should be or the easiest way for me to calculate it? Id appreciate any help because I have no clue what the f--k im doing and I dont want to mess my truck up.

 

You did not change your gears so your gears will remain the same. You enter 3.55. It is only the tires that changed. I did the same thing, only I went to 2.65/70/17s which calculates out to 2521. My gears remained at 3.55.

 

Good enough.. Thank you very much