I am currently running 295 BFG A/T with 4.10's and have found my speedo is somewhere around 6-8mph off. I also know this affects the odometer as you travel farther per revolution than with the stock tires.

This spring/summer I would like to move to a 305 possibly a 315 and recalibrate the speedo since it will be even further off. My question is how does the odometer take its reading? Will it be recalibrated with the speedo correction?

I would like to be able to calculate my mpg more accruately as right now im hitting 14-17mpg 75% highway no trailer, hand calculated, with power service.

 

The dealer can program the tire size if you figure out the revolutions per mile that your specific tire does. It's done through the ABS menu, and some will do it for free while others (such as mine), wanna charge you an arm and a leg for a 30 second procedure.

 

will this calibrate the odometer as well?

 

I'm pretty sure it will. Well, actually. 98.5's weren't digital displays were they? IIRC they had the older style dial-odometers, so I'm not entirely sure as that *probably* isn't computer driven.

There's a lot of assumptions in that paragraph.

 

yes, it is the digital display

 

You will need do have the dealer recalibrate it.

 

It should reflect the change in the odometer as well. If you have an overhead display that will also read what it *thinks* is right again. Although it's probably like 99% of them out there and is wrong anyways.