I recently got a new Edge Evo programmer and I am loving the new throttle response. I have 295/70/18 Nitto Trail Grapplers, I have done the math for my tire size and it comes out to 2646 in mm (thats what the edge asks for with tire size change). When I adjusted my tire size to that my speedomoter was now running about 3-4 mph slower than what the edge was showing. Once I moved it down to about 2600 mm then it is running about 2-3 mph slower then what the edge is reading. Does anyone have this programmer and these size tires? If so, how are you programming it? I want to get the correct shift points cause I know with the different tire sizes the shift points will be a bit different.

Any suggestions? thanks guys!

 

Your truck speedo will always be 2-3 mph fast. Ford builds them that way. Your adjustment to your original calculation took out some of the squish that the forula does not consider. Usually about 3%. The best method is to compare the Edge display to a gps.

 

x2....

 

Are these brand-spanking new tires? You could put a mark on your tire & driveway, roll the tire one complete revolution and then measure the distance between the original mark.

My GPS, speedo and Edge are all about 2-3 MPH off. Not that big of a deal for me - I typically drive 15 MPH over the speed limit anyway

 

Ok thanks guys, it wont effect my shift points if its a little off one way or the other? I will hook up the GPS this weekend and get it close. i would rather it be running faster on my speedo rather then lower, so it will save me some miles on my truck haha

 

https://www.f150online.com/forums/wh...tire-size.html