THanks for your thoughts. My 2004 XLT does not have the message center that you are referring to. So that is not an option.

I am glad to hear you say that the odometer should not be affected.

 

This should still work (using trip Odo reset button) on a normal odometer digital display.

 

If you've got the new body style F-150, you can do this. You don't have to have the Lariat/FX4 message center. It works on my XLT with the regular cluster. Also worked on my 2000 Focus with a similar display.

 

Ok I give up , tell me how. My 2004 is the new body style.

 

I have same situation with my 05. Speedo is 4-5 mph faster than actual speed (according to my GPS). I have LT245/70/17 tires. They turn 682 revs per mile. But in order to get my speedo to be accurate, I have to set my Xcal2 to 710 revs per mile. That gets me within about a 1mph difference at 60mph.

 

On my Expy, my Garmin is dead-on, but on my F150 it was off by 3 mph. After a new set of Michelins, my F150 is dead-on again.

I guess as the tires wore off, they it effected the speedo a bit.

 

Mine is off about 2-3 mph but A LOT of vehicles on the road are like this. . I think its better to read faster anyways, avoid some tickets!

 

Yep same here, Dodge GC right on 04 ford f150 is +3.

 

I don't know why Ford does this. I have 4 Fords parked in my drive and everyone of the speedo's is off by at least 2 mph according to my GPS units and using a stop watch and mile markers.

I understand the tire wear situation, but it does not make that much difference.

The good thing is that my 05 F150 work truck and my Ranger both have larger tires, so the speedo is right on now.

 

According to my Garmin Street Pilot, my speedo reads 4-5 mph faster at around 70mph. No wonder I'm always being tailgated lol.

 

https://www.f150online.com/forums/sh...ight=test+mode

See posts #3 and #10.

 

My speedo is off a few miles an hour from my Edge to factory speedo.


When I'm going 80 on Edge it says I'm going 82 on speedo.

 

My 2004 FX4 speedo has always been fast about 3MPH. You can see your real speed by holding in the odometer button when you start the engine then scroll thru until you get to speed. This readout should be accurate.