[JackandJanet]

Originally Posted by Joshg

Thank you all for all yor help it is very much appreciated! Also I have noticed over like a 10 mile distance my truck odometer ends up getting like 1/10 faster than the gps. Is than anything to worry about or can that just be that they are 2 diff devices reading 2 diff ways and they aren't synced together so they aren't gonna be dead accurate with each other??

It's nothing to worry about, but if your truck says 1/10 mile more than your GPS, you COULD have up to a 1% error in your Tire Size. My guess is, it's less than that, but your GPS granularity (precision), is 0.1, so the error is probably about 0.5%. That would equate to no more than 0.4 mph error in speed at 70 mph. (It would be very hard to "see" this error on your speedo.). But you could try reducing your TS by 0.5% which would be 2595.

- Jack

[Longshot270]

If you want the odometer to be dead on accurate, clear the odometers on both your truck and gps. Drive about 15-20 miles and enter the numbers into the following equation,

GPS odometer / Truck odometer * Current tire size = New tire size

More miles means more accuracy.