My speed on my Edge reads almost 5 mph slow compared to the truck, is there any way to up the speed on the edge? Which is more accurate, the truck speedo, or the Edge, and does changing the tire size on the Edge change the truck speedo also, or just the speed on the Edge?

 

Changing the speed on the Edge changes the truck as well. Two to three mph is normal, 5 is more than normal. The best way is to get the Edge set accurately with a GPS and forget about the truck speedo.

 

What edge model?

You may have to decrease the tire size number by 2%-3%

 

We don't really know which way he'll need to go 88, since he didn't say if either of the speeds was accurate. And, we don't know what speed he's talking about either. Until he "clocks" his truck with a GPS or compares distance with mile markers and compensates, both the Edge and the dash can be, and probably are, wrong.

However, as Bluejay said, a difference of 5 mph is way beyond normal. "Adjusting" your dash speedo to read the same as the Edge is probably quite complicated, but if the OP gets the Edge to read correctly, like Bluejay said, then he can "mentally" correct the dash reading.

- Jack

 

The dash is fairly accurate, I checked it on the highway and my GPS. The Edge may only be about 3 mph low, it's hard to tell it changes alot while going down the road. As if I were going 60 on the truck speedo, the Edge reads maybe 56-58. I have the Evo model. I know changing the tire size a bit on the Edge will correct it. But I don't want the truck speedo to change also. Normally I don't have the speed displayed on the Edge, but I figure my MPG's may read more accurate if the speed on it was correct.

 

I highly doubt the dash speedo is accurate. Ford builds them to be 2-3 mph fast. The Edge, on everyone else's is the accurate reading. If you adjust tire size, it WILL adjust the dash, no way around it. You just have to decide, do you want to be going slower than you think you are or do you want the Edge correct and the truck where Ford intended it to be. If your dash speedo is accuarte, it would be the first we have heard of, and there have been hundreds.

 

AND, since there are "no moving parts" in the Edge, it is reporting what the PCM thinks your speed is. If your Tire Size is correct, THAT speed is the correct speed.

Play with the TS until your Edge speed matches the GPS. Increase TS if the Edge reads slow and vice-versa. Once you get your Edge speed accurate, the dashboard odometer will also be accurate (no moving parts) and you can see what your dashboard speedo error is.

- Jack

 

My Gryphon is two mph slower than my GPS and 4 mph slower than my dash speedometer..

 

X2.....
Probably a squish thing not being accounted for....

 

I kept a closer eye on it this evening, it's about 2.5 mph difference. I set the cruise at 60 and the edge would read 57-58. That's liveable. At first glance I thought it was about 5 off.

 

That explains why I've never gotten a ticket.