I have programmed the predator to change my speedo for 285 75r16 tires and also changed the tire size with the edge/attitude. Now the attitude shows me going faster than the factory speedometer. say at 65mph on the speedo, the attitude shows 71mph...........which one do I believe. One last thing, my tires are actually 33 x 12.50 r16, so I had to program both units with 285/75 r16.
thanks for the help in advance.

Use mile markers on the freeway and a stop watch (60mph = 1 mile a minute) or a GPS.

I believe the reason the Attitude is getting confused is because the Predator already modified the speed signal, but I could be wrong.

Yeah I would bet the edge is double correcting since the signal it gets from the computer is already corrected now that you changed it with the predator..

Larry,
I have corrected my speedo with the Predator and my edge still reads correctly. See if you can borrow someones GPS. Also, when I entered my tire size into the Predator the speedo was off. I changed it until the speedo was within .5 mph or better at 65 mph.

remove the tire settings on the Edge and have only one programmer making the change.. see if that helps. Like someone said.. one is correcting a setting that is also being corrected.