their are so many things discussed on these forums, which contain variables..... But this isn't one of them ;-)

If you go to a larger tire diameter, your vehicle will go "faster" than your speedometer tells you it is, and it will travel farther than your odometer tells you it has. Always. Regardless of the vehicle.

BTW, I'm still trying to get my onboard computer "reflashed" to correct the speedo / odo for my larger tires. I've been told by Ford, that with my modest 33"s, this won't be a problem. The only problem is, Ford wants $220 to do it. My local offroad place only charges $75..... But they do not have thier hardware updated (with the software needed) to reflash an 08' F150 :-( I've been bugging them for months. I'm about to start looking elsewhere.......

Peace,
Fish

 

I went from stock 265/60R18 to 285/65R18 and my Speedometer is only 2 mph off based on 3 different law enforcement agencies checking it for me. And when I checked mile marker to mile marker I was barely off, meaning that when I hit the 1 mile my odometer was at .9+ turning to next mile close to the mile marker. So I don't see any changes
based on my new setup. I still get 14-16 MPG all around - I didn't buy my truck to save gas, although getting 16-18 would make me happier LMAO!