Just bought a used truck and it has this with it. The speedo is off anything over 55 mph. I only know this because my speedo will show I'm going 75, rpms are around 1700 and I'm getting passed left and right. I know there is a way to have it set to the tire size (305x55r20) I just don't know how to do it. The truck didn't come with a Manuel for the edge or anything. I need some help!!

Oh and merry Christmas!!!!

 

Merry Christmas! Maybe this pdf will help it shows on page 16.Here is the link of the manual.... https://edgeproducts.com/installation_guides/15051.pdf