Tire size and Nav sytem

[Greg250]

I am about to buy some BFG AT's - 265/70/17 - anyone know how this will effect the nav system? I realize the spedo and the mileage will be off by 3.4%.

Does anyone run this size tire with a Nav system?

 

[Faeylyn]

It's GPS-based. It doesn't care what size your tires are.

 

[Greg250]

I thought it used a combination of vehicle speed and GPS reception. There is a 'calibration' option in the NAV set-up screen for new tires, but it assumes you are replacing them with the original tire size. There is no option for changing tire diameter.