2018 XLT. Speedo differs from phone GPS using apps with speedo. Normally about a solid 8-10 mph faster displayed on GPS speed versus truck. So at 60 mph on truck speedo the phone apps will show 68-72. That stays about the same at all speeds. I set 60 and it will knock out a mile in exactly 1 minute. Not sure whats going on. The phone gps will match any other vehicle's speedo that I use it in. There is no way I'm doing 95 on the interstate like the phone says I am. Any ideas?

 

If you swapped out wheels you need to have your speedo recalibrated to match the new revs from the size change.

 

No changes to vehicle.

 

Have you tried different apps? I can’t think of any other situation that would warrant a difference like that.

 

Yup. Waze, a couple different speedo apps. Both of the speed apps clock accurately in different cars and even my helicopter.

 

I checked my speedometer with a GPS shortly after getting my '15 (7/17/15). It was dead on. If I dropped by 1MPH, the GPS would drop 1MPH, and if I increased 1MPH, the GPS would increase 1MPH:

 

This sounds silly, I know, but have you tried a different phone or GPS device? Even compared it to the roadside warning radar the police set up?

 

Are you using actual satellite GPS or tower data? There's really no way to fudge up if going off satellite, unless someone is faking GPS signals in your area. Do you drive the truck a specific route? Other vehicles the same route?

 

Satellite. No specific route. It’s the same everywhere. I’ll use the wife’s phone when home from this trip.

 

Accidentally switching the phone to kmh when in the truck? I think we've covered all the bases on this.