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!

 

Did you account for the 4-5% "squish" in your original calculations?

Edit: I calculated it out and 2600 is about where you should be. GPS is the only real way to accurately know the true speed to find which display is closer.

 

295/70/18 Nitto Trail Grapplers
http://nittotire.com/index.html#inde....trailgrappler
size 34.7 revs 600

these are the specs that I would put into my programmer for the correct speedo reading but I own a SCT X3

 

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

 

I forgot one thing because my custom tune takes this into consideration. Gear ratio!

gear ratio, tires size, revs

my set up: my speedo is right on! cked with GPS

gear ratio, tires size, revs

4:56 35.5 580

 

I have Discoverer ST's - 285/70-17 Load range D and I use 2400mm flat on my gryphon. It's still a bit off... My speedo is DEAD ON according to two GPS units and the edge is ~10-~15 OVER my actual speed. Weird, and I got fed up trying to figure it out.

 

i installed my edge today and went on to the tire size option to change my tire size, but it wont let me, it reads as something about manufacture calibration. dose anyone know about this issue?